Create tags through GH when release PR is merged

[sozercan]

Describe the solution you'd like Create release tags to kick off the release of artifacts and binaries. pull_request is the event that we can use for this.

https://github.com/open-policy-agent/gatekeeper/issues/3037

Anything else you would like to add: [Miscellaneous information that will assist in solving the issue.]

Environment:

• Eraser version:
• Kubernetes version: (use kubectl version):