Update Squid-6 series status (#40)

also update web links

Author: yadij

docs/Releases/Squid-6.md

@@ -2,13 +2,11 @@
 
 |       |                               |
 | ----- | ----------------------------- |
-| current | Now in **DEVELOPMENT** cycle. |
+| Jul 2025 | Squid-6 series became **DEPRECATED** with the release of [Squid-7](/Releases/Squid-7) series |
+| JUl 2023 | Released for production use. |
 | | |
 
-The set of new features is determined by submissions and available
-developer time. New features may be completed and added at any time.
-Features accepted before 2023-02-05 (see
-[ReleaseSchedule](/ReleaseSchedule)) will be part of this release.
+No more changes or releases will be done for the Squid-6 series.
 
 ## Basic new features in 6.0:
   - **Major UI changes:**
@@ -39,22 +37,20 @@ Features accepted before 2023-02-05 (see
       - Remove obsolete membanger test
       - Remove deprecated leakfinder (--enable-leakfinder)
 
-Packages of what will become Squid-6 source code are available at
-http://www.squid-cache.org/Versions/v6/
+Packages of Squid source code are available at <https://www.squid-cache.org/Versions/>
 
 ## Security Advisories
 
-See our [Advisories](http://www.squid-cache.org/Advisories/) list.
+See our [Advisories](https://github.com/squid-cache/squid/security/advisories?state=published) list.
 
 ## Open Bugs
 
   - [Major or higher bugs currently affecting this
-    version](http://bugs.squid-cache.org/buglist.cgi?bug_id_type=anyexact&bug_severity=blocker&bug_severity=critical&bug_severity=major&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&chfieldto=Now&product=Squid&query_format=advanced&columnlist=bug_severity%2Cversion%2Cop_sys%2Cshort_desc&order=version%20DESC%2Cbug_severity%2Cbug_id&o2=equals&v2=unspecified&f1=version&o1=lessthaneq&v1=6).
+    version](https://bugs.squid-cache.org/buglist.cgi?bug_id_type=anyexact&bug_severity=blocker&bug_severity=critical&bug_severity=major&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&chfieldto=Now&product=Squid&query_format=advanced&columnlist=bug_severity%2Cversion%2Cop_sys%2Cshort_desc&order=version%20DESC%2Cbug_severity%2Cbug_id&o2=equals&v2=unspecified&f1=version&o1=lessthaneq&v1=6).
 
-      - Bugs against any older version can be closed if found fixed in
-        6.x
+      - Bugs against any older version can be closed if found fixed in 6.x
 
 <!-- end list -->
 
   - [Bugs new in this
-    version](http://bugs.squid-cache.org/buglist.cgi?query_format=advanced&product=Squid&version=6&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&bug_severity=blocker&bug_severity=critical&bug_severity=major&bug_severity=normal&bug_severity=minor&emailtype1=substring&email1=&emailtype2=substring&email2=&bugidtype=include&columnlist=bug_severity%2Cversion%2Cop_sys%2Cshort_desc&list_id=917&order=version%20DESC%2Cbug_severity%2Cbug_id)
+    version](https://bugs.squid-cache.org/buglist.cgi?query_format=advanced&product=Squid&version=6&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&bug_severity=blocker&bug_severity=critical&bug_severity=major&bug_severity=normal&bug_severity=minor&emailtype1=substring&email1=&emailtype2=substring&email2=&bugidtype=include&columnlist=bug_severity%2Cversion%2Cop_sys%2Cshort_desc&list_id=917&order=version%20DESC%2Cbug_severity%2Cbug_id)