Use Gradle 8.11 as the minimum version for cache-cleanup

The cache-cleanup API has changed, so the init-script that worked with
Gradle 8.9 no longer works with 8.11.
We now provision and use Gradle 8.11 for cache cleanup.

This provides a band-aid fix for #417 but that issue will still impact
any build configured to run with Gradle > 8.11

.github/workflows/ci-check-and-unit-test.yml

@@ -28,7 +28,7 @@ jobs:
       env:
         ALLOWED_GRADLE_WRAPPER_CHECKSUMS: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 # Invalid wrapper jar used for testing
       with:
-        gradle-version: "8.10.2"
+        gradle-version: "8.11"
 
     - name: Check formatting and compile
       run: |