Refactor update ci/cd workflow remove deployment improve performance

[jeffcumpsty-tpx]

🚀 CI/CD Modernisation & Performance Refactor

I have reorganized the ci.yml workflow. The total execution time has been reduced from ~6 minutes to approximately 3 minutes.

• delete the gitHub action called Enforce Staging to Main only. The new script includes the branch-gate job which performs the same check.
• set branch protection rules for staging and main to ONLY be dependant on the workflow-status/Final Workflow Status GitHub action. You will need to do this after you merge the changes into each branch or future pull_request or push actions will fail due to being dependant on actions which do not exist.,

⚡ Parallel Execution

• Optimised Dependencies: Reorganised job logic so that security-scans and docker-and-dast now run simultaneously immediately after a successful build.
• Impact: Significantly reduced total wall-clock time by removing the previous linear bottleneck.

🛡️ Gatekeeper Pattern & Branch Logic

• Integrated Branch Gate: Added a branch-gate job directly into the workflow to enforce the Staging → Main flow.
• Workflow Status (Gatekeeper): Introduced a workflow-status job to act as a single synchronisation point. It validates all parallel tasks, ensuring the pipeline is healthy even when the release task is skipped (e.g., on staging pushes).
• Cleanup: The separate staging-to-main.yml workflow is now redundant and can been deleted.

Important

🛠️ Required Action: Update Branch Protection Rules

To complete this migration, please update the GitHub repository settings:

1. Staging and Main: Update rules to ONLY rely on the status check: Final Workflow Status.

☁️ Heroku Deployment

• Removal: Heroku Deployment jobs have been completely removed from this branch.
• Supersession: This branch supersedes refactor--remove-Heroku-deployment-jobs.... If that branch has not been merged yet, it can be deleted.

ready for review