Gradle 8.8 introduces new features that allow us to avoid using
timestamp manipulation to force the cleanup of the Gradle User Home directory.
This solution is simpler and more robust, but relies on Gradle 8.8+ always being
used for the cache cleanup operation.
Fixes#24
To cleanup Gradle User Home, a Gradle build must be executed.
Newer Gradle versions are able to cleanup the home directories of older versions,
but not vice-versa.
With this change, the latest version of Gradle is automatically provisioned
in order to run Gradle User Home cleanup. This ensures a consistent version of
Gradle is used for cleanup, and fixes#33 where Gradle is not pre-installed on
a custom runner.