Add workflow to automate feature release tasks in the org

This workflow takes the following inputs:
* BRANCH_NAME - release branch name, e.g. 18.0-fr4
* NEW_VERSION - The new version to set in the Makefile on the
  main/source branch, e.g. 0.5
* FORCE_BUMP_BRANCHES - The new list of branches for the
  force-bump-branches.yaml workflow, e.g. ["main", "18.0-fr3"]
* DRY_RUN - Bool to run in Dry mode to not push changes

This workflow does the following tasks:
- BRANCH_NAME updates:
* checks every repository in the org for an olive branch. If it
  exists, the new BRANCH_NAME gets created from main
* each Makefile of the BRANCH_NAME, the Makefile gets updated to
  set the feature branch
* in case of install_yamls, the OPENSTACK_K8S_TAG gets updated in
  the Makefile for the feature branch

- openstack-operator main branch updates:
* Updates Makefile to reflect the NEW_VERSION
* updates hack/fake_minor_update.sh for the NEW_VERSION
* updates .github/workflows/catalog-openstack-operator-upgrades.yaml
  for the version change

- Update openstack-k8s-operators-ci workflows
* updates .github/workflows/release-branch-sync.yaml for the new
  BRANCH_NAME
* updates .github/workflows/force-bump-branches.yaml for the new
  FORCE_BUMP_BRANCHES

- Add rabbitmq-cluster-operator-index tag for the branch
* calls .github/workflows/rabbitmq-cluster-operator-index-feature-tag.yaml
  to push a new tag for the BRANCHE_NAME

Note: this workflow requires authentication using a GitHub App with
permissions to read/write content of the repos and workflows.

Depends-On: openstack-k8s-operators#135
Depends-On: openstack-k8s-operators/openstack-operator#1539
Depends-On: openstack-k8s-operators/openstack-operator#1540

Jira: OSPRH-18397

Assisted-by: gemini
Signed-off-by: Martin Schuppert <mschuppert@redhat.com>

Author: stuggi