add release workflow

[pdabelf5]

Proposed changes

Add workflow to release using separate workflow from the main ci.yml flow.

This workflow can be called as many times as needed without needing to re-tag. Has a dry run option.

Inputs

input.nic_version # The NIC version to release, e.g. 3.6.0 - required
input.source_tag # The tagged image to release, e.g. release-3.6 - optional, will use image sha by default (image sha is a future feature)
input.chart_version # The helm chart version to release, e.g. 1.3.0 - required
input.cnab_version # The CNAB version to use for triggering the Azure Marketplace CNAB build, e.g. 1.0.4 - optional, required when running the azure-marketplace job
input.release_branch # The release branch name to build from, e.g. release-3.6 - required
input.dry_run # Run the release workflow in dry run mode, i.e. don't actually do anything - optional
input.skip_step # Comma separated list of steps to skip, e.g. publish-helm-chart,operator,aws-marketplace,azure-marketplace,gcp-marketplace,github-release,release-image-notification.  Defaults to an empty string

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork