chore: Add ^release- branches for on-push Konflux builds

[msugakov]

This should enable Konflux builds from release branches for the case when SCANNER_VERSION points to a tag/commit that was on a release branch, not on master.

See also: https://redhat-internal.slack.com/archives/C079XCJEZK6/p1721729454430659?thread_ts=1721678052.993799&cid=C079XCJEZK6

Prerequisite for https://issues.redhat.com/browse/ROX-24468.

Available CEL functions are here https://github.com/google/cel-spec/blob/master/doc/langdef.md#list-of-standard-definitions.

[RTann]

LGTM though I don't know why those "acs-enterprise-contract" jobs are failing. When I click on them the UI either gives me a 502 or says the logs don't exist

[RTann]

So this will capture all pushes to the release branches, right? Do we want that or to just capture all tag events (if that's posible)?

[msugakov]

Thanks for the approval Ross

Regarding acs-enterprise-contract: it's unfortunately broken for all our Konflux builds. We look into this.
It's not stable yet and failures are more common than successes. Additionally, there are sporadic problems with Konflux Console.
It's fine :-) ...for now.

Regarding tags: it's a good question, and we can match on tags (example here) but at this point I fully don't know what we need yet.
I think, running Konflux on pushes to release branches which are not just tags has a benefit of giving a CI signal whether the release branch builds well.

I suggest we start like this and later see how to adjust. We can configure to build on tags in addition or instead of building on release branches, when needed.