Setup GitHub Release for Production Deployments

[NEStock]

I'd like to suggest that we revert back to using GitHub Releases to start the production deploy and have a single default prod (or differently named) branch that sandbox (and production) deploys from.

Pros:

• Prevent the curret "double" PR workflow that we have to do now
• Clean up our commit history
• Makes the merging more straightforward

For reference, our current workflow is as follows:

1. new branch for an issue <issue-branch>
2. merge <issue-branch> into sandbox
   a. sandbox branch is deployed to the sandbox URLs
3. merge sandbox to prod
   a. prod branch is deployed to the “real” URLs dandi.emberarchive.org

Welcome additional thoughts & pros/cons!