gradle-wrapper.properties still sits at 8.9

There's apparently a hole in the release scripting and the gradle-wrapper.properties did not get updated contrary to the release notes that claim gradle was upgraded to 9.1.

Start by inspecting gradle-wrapper.properties and the release notes referenced in the issue, then trace the release scripting that should update the wrapper version. Done means the wrapper reflects Gradle 9.1 as stated in the release notes and the release process no longer leaves it at 8.9.

Written by the indexing model from the issue text.