Add release note about patch release quick check (deephaven#5507)

RELEASE.md

@@ -133,6 +133,9 @@ $ git --no-pager log --oneline vX.Y.0..release/vX.Y.1
 # Compare output to expected PR list for missing or extraneous PRs
 ```
 
+It's also best practice to ensure that the cherry-picks compile, as there can sometimes be changes that cherry-pick cleanly, but don't compile.
+`./gradlew quick` is recommended as a quick validation that things look ok.
+
 ### 3. Push to upstream
 
 Triple-check things look correct, the release is a "GO", and then start the release process by pushing the release branch to upstream: