cd: release single rc version

[aabouzaid]

Which problem does the PR fix?

Task: https://github.com/camunda/distribution/issues/378

What's in this PR?

Release a single RC version and reset the RC branch.

Checklist

Please make sure to follow our Contributing Guide.

Before opening the PR:

• In the repo's root dir, run make go.update-golden-only.
• There is no other open pull request for the same update/change.
• Tests for charts are added (if needed).
• In-repo documentation are updated (if needed).

After opening the PR:

• Did you sign our CLA (Contributor License Agreement)? It will show once you open the PR.
• Did all checks/tests pass in the PR?