Automation v4.5.6 for OCP 4.5.x stable release

What's Changed

• Cluster upgrade using stable versions by @yussufsh in #193
• trigger for upgrade resource by @Prajyot-Parab in #197
• Handle install after bootstrap is deleted by @yussufsh in #204
• Allow adding and deleting worker nodes by @yussufsh in #207
• update helpernode and install-playbook tags by @Prajyot-Parab in #214
• Create Terraform vars for test/dev cluster, CP4D, etc for release branch 4.5 by @aishwaryabk in #219
• Add variable for bastion health_status by @yussufsh in #235
• Support using catalog/stock images from PowerVS by @yussufsh in #237
• [release-4.5] Update the doc for Power support #239 by @ltccci in #245
• [release-4.5] Added a reviewer and removed an appover by @ltccci in #254
• Notice for EOL by @yussufsh in #329

Full Changelog: v4.5.5...v4.5.6