This removes the remaining usage of `mapping.single_type` from the parent join
module and moves it's bwc test to the mixed cluster tests
Relates to #24961
Relates to #20257
This commit adds a gradle project, set inside the root build.gradle,
which controls all our bwc tests. This allows for seamless (ie no errant
CI failures) backporting of behavior.
Removes the need for the `_UNRELEASED` suffix on versions by detecting if a version should be unreleased or not based on the versions around it. This should make it simpler to automate the task of adding a new version label.
This commit renames the backwards-5.0 qa test to mixed-cluster and
creates a test within the project per wire compat version. Like with
rolling upgrade tests, the integTest task will run against the most
recent version, while all versions will be tested with the bwcTest task.
Simon Willnauer
Ryan Ernst
Nik Everett