Fix remaining Antora errors in cassandra-website content

Second batch of broken-xref / broken-asset fixes on the asf-staging
source tree:

- blog/Apache-Cassandra-Changelog-{19-September,20-November}-2022.adoc:
  replace rendered-site xref target doc/latest/cassandra/architecture/
  overview.adoc with the Antora component-qualified form
  Cassandra:cassandra:architecture/overview.adoc.
- blog/Apache-Cassandra-Changelog-20-November-2022.adoc: remove a space
  that had crept into the xref target for the Cassandra-Day-SC-Bellevue-
  Houston-WakandaForever.adoc file.
- glossary.adoc: remove three include directives that referenced partials
  never present in this repo (persistent-volume, persistent-volume-claim,
  segment).
- download.adoc: rewrite image target from absolute rendered URL
  /assets/img/caution.svg to the Antora-relative form caution.svg (the
  asset lives in modules/ROOT/images/).
- apachecon_cfp.adoc: remove reference to /img/apachecon-2019.jpg, an
  asset that was lost during the 2020 Jekyll-to-Antora migration
  (CASSANDRA-16066). Surrounding 2019 archival prose stays intact.

Local verification via xref-report.sh delta against the post-batch-1
build: 8 of 9 targeted errors demonstrably resolved (total went from 9
to 3). Remaining 3 errors (2 from the architecture/overview rewrites,
1 from the main-nav Cassandra::index.adoc reference) all depend on the
Cassandra component being present in the Antora build. The local
verification build was a minimal website-only run (no -g flag) that
does not import the Cassandra component, so these three cannot be
validated locally; the Jenkins build resolves the Cassandra component
from multiple version sources and is the authoritative test for them.

The main-nav Cassandra::index.adoc xref was NOT touched in this commit.
Root cause analysis shows cassandra/doc/antora.yml declares the 6.0
version as prerelease, which disqualifies it as the default target for
unversioned xrefs. Fix direction (un-prerelease, pin a version, or
re-point the nav) is production-config-sensitive and left for a
separate ticket.

 patch by Patrick McFadin; reviewed by Brandon Williams for CASSANDRA-21342

Author: pmcfadin

site-content/source/modules/ROOT/pages/apachecon_cfp.adoc

@@ -12,9 +12,6 @@ Summit, hosted with ApacheCon in Las Vegas, NV (Sept 9 - 13).
 
 === Apache Cassandra at ApacheCon
 
-image:/img/apachecon-2019.jpg[ApacheCon 2019]\{:style=``float: right;
-width: 400px''}
-
 For more information about other events at ApacheCon, see
 https://apachecon.com/acna19/index.html[ApacheCon 2019].
 

site-content/source/modules/ROOT/pages/blog/Apache-Cassandra-Changelog-19-September-2022.adoc

@@ -37,7 +37,7 @@ To stay up-to-date, we recommend joining the xref:community.adoc#discussions[Cas
 
 _Updates on Cassandra Enhancement Proposals (CEPs), how to contribute, and other community activities._ 
 
-_For newcomers to the project, we have a useful xref:development/index.adoc[‘Contributing to Cassandra’] page for how to get involved and get started. We would also recommend reading the xref:doc/latest/cassandra/architecture/overview.adoc[overview of the C* architecture^]._
+_For newcomers to the project, we have a useful xref:development/index.adoc[‘Contributing to Cassandra’] page for how to get involved and get started. We would also recommend reading the xref:Cassandra:cassandra:architecture/overview.adoc[overview of the C* architecture^]._
 
 _We use Jira to record project issues. Here’s a handy Jira tip from *Josh McKenzie*: if you want to search for tickets in your area of interest, use this https://issues.apache.org/jira/issues/?jql=project%20%3D%20cassandra%20AND%20resolution%20!%3D%20unresolved%20AND%20assignee%20is%20EMPTY%20AND%20summary%20~%20%27ReplaceTextHere%27%20ORDER%20BY%20priority%20ASC[URL link^]. Simply swap out ‘ReplaceTextHere’ in the URL query string for what you want to find._
 

site-content/source/modules/ROOT/pages/blog/Apache-Cassandra-Changelog-20-November-2022.adoc

@@ -35,7 +35,7 @@ To stay up-to-date, we recommend joining the  xref:community.adoc#discussions[Ca
 
 _Updates on Cassandra Enhancement Proposals (CEPs), how to contribute, and other community activities._ 
 
-_For newcomers to the project, we have a useful xref:development/index.adoc[‘Contributing to Cassandra’] page for how to get involved and get started. We would also recommend reading the xref:doc/latest/cassandra/architecture/overview.adoc[overview of the C* architecture]._
+_For newcomers to the project, we have a useful xref:development/index.adoc[‘Contributing to Cassandra’] page for how to get involved and get started. We would also recommend reading the xref:Cassandra:cassandra:architecture/overview.adoc[overview of the C* architecture]._
 
 We use Jira to record project issues. Here’s a handy Jira tip from *Josh McKenzie*, if you want to search for tickets in your area of interest, use this https://issues.apache.org/jira/issues/?jql=project%20%3D%20cassandra%20AND%20resolution%20!%3D%20unresolved%20AND%20assignee%20is%20EMPTY%20AND%20summary%20~%20%27ReplaceTextHere%27%20ORDER%20BY%20priority%20ASC[URL link^]. Simply swap out ‘ReplaceTextHere’ in the URL query string for what you want to find.
 
@@ -147,7 +147,7 @@ video::ZbJrFy4TlNI[youtube,640,360]
 
 xref:blog/Cassandra-Days-Asia-2022.adoc[Cassandra Days Asia - Hanoi, Jakarta, Singapore] - Erick Ramirez
 
-xref:blog/Cassandra-Day-SC-Bellevue-Houston-Wakanda Forever.adoc[Cassandra Day Santa Clara-Bellevue-Houston + Wakanda Forever] - Erick Ramirez
+xref:blog/Cassandra-Day-SC-Bellevue-Houston-WakandaForever.adoc[Cassandra Day Santa Clara-Bellevue-Houston + Wakanda Forever] - Erick Ramirez
 
 xref:blog/Cassandra-Summit-Returns-in-2023.adoc[Cassandra Summit Returns in 2023] - Cassandra Community
 

site-content/source/modules/ROOT/pages/download.adoc

@@ -182,7 +182,7 @@ https://repo.maven.apache.org/maven2/org/apache/cassandra/[Maven Central,window=
 
 [CAUTION]
 ====
-image:/assets/img/caution.svg[alt="Caution",width=64,height=64]  Debian and RedHat package repositories have moved!
+image:caution.svg[alt="Caution",width=64,height=64]  Debian and RedHat package repositories have moved!
 
 Debian's `sources.list` and RedHat's `cassandra.repo` files must be updated to point to the new repository URLs (see below).
 ====

site-content/source/modules/ROOT/pages/glossary.adoc

@@ -251,10 +251,6 @@ include::ROOT:partial$partition-summary.adoc[]
 
 include::ROOT:partial$partitioner.adoc[]
 
-include::ROOT:partial$persistent-volume.adoc[]
-
-include::ROOT:partial$persistent-volume-claim.adoc[]
-
 include::ROOT:partial$primary-key.adoc[]
 
 :leveloffset: -2
@@ -295,8 +291,6 @@ include::ROOT:partial$alphabet-nav.adoc[]
 
 include::ROOT:partial$seed.adoc[]
 
-include::ROOT:partial$segment.adoc[]
-
 include::ROOT:partial$serializable-consistency.adoc[]
 
 include::ROOT:partial$stcs.adoc[]