ci: restore version bumping via craft preReleaseCommand (#5261)

* ci: restore version bumping via preReleaseCommand

#skip-changelog

Craft 2.26.6's built-in nuget auto-bumper looks for the `dotnet-setversion`
CLI and, when not found, falls back to a "manual edit" heuristic that does
not recognize `Directory.Build.props`. It downgrades the failure to a warn
and lets prepare continue, so the `release: 6.6.0` commit only updated
CHANGELOG.md and the resulting nupkg files were named `*.6.5.0.nupkg`.

The repo's own scripts/bump-version.sh already rewrites <VersionPrefix>
correctly. Wire it back in via craft's preReleaseCommand, as the warning
in the prepare log recommends.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* chore: fix typo (convension -> convention) in bump-version.sh

#skip-changelog

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Author: jamescrosswell

.craft.yml

@@ -1,5 +1,6 @@
 minVersion: 2.26.3
 changelogPolicy: auto
+preReleaseCommand: bash scripts/bump-version.sh
 targets:
   - name: nuget
   - name: github

scripts/bump-version.sh

@@ -3,5 +3,5 @@
 set -eux
 
 # Requires powershell: `brew install powershell`
-# craft executes this file by convension, passing the new version as the second argument:
+# craft executes this file by convention, passing the new version as the second argument:
 pwsh ./scripts/bump-version.ps1 $2