[GEOS-12049]: GWC Removing inMemory caching

[dromagnoli]

Removing MemoryBlobStore and anything related to that since it was causing deadlocks
https://osgeo-org.atlassian.net/browse/GEOS-11953

The removal requires GeoServer to be updated too:
geoserver/geoserver#9098
(The downstream integration build failure is expected before merging that)

[aaime]

Looks good to me. The memory caching as implemented is more of a bug than a feature, I agree removing it is a good course of action.

[geoserver-bot]

The backport to 1.28.x failed:

The process '/usr/bin/git' failed with exit code 1

stderr

error: could not apply df0e7799a... [GEOS-12049]: Removing inMemory caching
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config set advice.mergeConflict false"

stdout

Auto-merging geowebcache/core/src/main/java/org/geowebcache/GeoWebCacheDispatcher.java
Auto-merging geowebcache/diskquota/core/src/main/java/org/geowebcache/diskquota/rest/controller/DiskQuotaController.java
CONFLICT (modify/delete): geowebcache/distributed/pom.xml deleted in df0e7799a ([GEOS-12049]: Removing inMemory caching) and modified in HEAD.  Version HEAD of geowebcache/distributed/pom.xml left in tree.
Auto-merging geowebcache/pom.xml
CONFLICT (modify/delete): geowebcache/rest/src/main/java/org/geowebcache/rest/controller/MemoryCacheController.java deleted in df0e7799a ([GEOS-12049]: Removing inMemory caching) and modified in HEAD.  Version HEAD of geowebcache/rest/src/main/java/org/geowebcache/rest/controller/MemoryCacheController.java left in tree.
CONFLICT (modify/delete): geowebcache/rest/src/test/java/org/geowebcache/rest/statistics/MemoryCacheControllerTest.java deleted in df0e7799a ([GEOS-12049]: Removing inMemory caching) and modified in HEAD.  Version HEAD of geowebcache/rest/src/test/java/org/geowebcache/rest/statistics/MemoryCacheControllerTest.java left in tree.
Auto-merging geowebcache/web/src/main/webapp/WEB-INF/geowebcache-core-context.xml
Auto-merging geowebcache/web/src/test/java/org/geowebcache/jetty/RestIntegrationTest.java

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-1.28.x 1.28.x
# Navigate to the new working tree
cd .worktrees/backport-1.28.x
# Create a new branch
git switch --create backport-1471-to-1.28.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick df0e7799a59f029532469002e34be77ea7cc65b9
# Push it to GitHub
git push --set-upstream origin backport-1471-to-1.28.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-1.28.x

Then, create a pull request where the base branch is 1.28.x and the compare/head branch is backport-1471-to-1.28.x.

[dromagnoli]

Backported with this:
#1474