[DISCO-2280] Add 'check-for-deployment' and 'unhold-to-deploy' jobs to the Contile CI main-workflow-

References

Description

In order to empower contributors to skip deployments (example: for documentation changes) and control the flow of changes to staging and production environments, introduce the check-for-deployment and unhold-to-deploy jobs to the Contile CI main-workflow.

Resource

Example: Merino CI workflows

Adding approval jobs to your CI pipeline

Acceptance Criteria

A check-for-deployment job is incorporated into the Contile CI main-workflow

It’s purpose is to detect the “[do not deploy]” text within the merge commit when merging the PR to the 'main' branch and to subsequently stop stage and production Docker Hub image publications.

An unhold-to-deploy job, or approval task, is incorporated into the Contile CI main-workflow

This job will wait for manual confirmation from a contributor before deploying the production Docker Hub images

The CONTRIBUTING.md, the PULL_REQUEST_TEMPLATE.md and any other relevant documentation is updated

PR Review Checklist

Put an x in the boxes that apply

[x] This PR conforms to the Contribution Guidelines
[x] This PR conforms to the Opsec policies
[ ] Functional and performance test coverage has been expanded and maintained (if applicable)
[x] Documentation has been updated
[x] The PR title starts with the JIRA issue reference, format [DISCO-####], and has the same title

mozilla-services / contile