This change also fixes `finalizing release` workflow
https://github.com/cozystack/cozystack/pull/890#issuecomment-2830525103
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **Chores**
- Updated release tag validation to require a dot between "rc" and the
number (e.g., `v0.31.5-rc.1` instead of `v0.31.5-rc1`).
- Adjusted error messages to reflect the new release tag format.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Signed-off-by: Andrei Kvapil <kvapss@gmail.com>
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **Chores**
- Improved reliability of GitHub Actions workflows by ensuring only one
job per pull request or branch runs at a time. If a new workflow run is
triggered, any previous in-progress runs for the same group will be
automatically canceled, preventing overlapping executions.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
