[Release automation] Prerelease and stable tag

[jbordonado]

Description

Introduce the concept of prerelease and a way to flip the stable tag.

Acceptance criteria

• First requirement
• Second requirement
• Third requirement
• etc.

Designs

Testing instructions

1. Go to '…'
2. Click on '…'
3. Scroll down to '…'
4. Observe expected behaviour

Dev notes

I spotted a function in woorelease: update_stable_tag

Additional context

[jbordonado]

Food for thoughts regarding releasing beta versions without bumping the stable tag: p1667407908157659/1667311794.884079-slack-C01BPL3ALGP

[jbordonado]

Another thing to consider: https://wcpay.wordpress.com/2023/03/10/atomic-first-release-for-woocommerce-payments-5-6-0/

The goal here was to first deploy on Atomic, and if everything's fine, make the version publicly available on WP.org.

The steps were:

• deploy to WP.org a package without stable tag change and changelog change (changelog is pulled automatically by WCCOM)
• request Atomic to pin the new version so it's available for all Atomic sites

If all is well:

• Add back the stable tag update and changelog entries to the zip file, and deploy it to WP.org

If not:

• create a patch version (which we can either decide to release first on Atomic using the same steps as above or directly public on WP.org)