ci: add new release process based on release-please

[hf]

Adds a new release process based on release-please.

As soon as this gets merged, releases will work as follows:

1. PR merges will be collected by release-please into a release PR. The team at Supabase decides when a release is ready to go out, usually weekly or bi-weekly.
2. Every PR merge (that uses feat: or fix: titles) will result in a release candidate release with tag rc<version>. Example: if the new release will be 2.140.0 then the RC release will be rc2.140-rc.1, and so on.
3. Once the release PR is merged, an official release will be published with the tag v<version>, or per the example v2.140.0.
4. Releases with a patch version of 0 get a special branch release/v2.140.0 which can be used to patch that and only that major+minor version, using the same process as above.
5. RC releases are tagged rc in NPM and regular ones as latest. Patched releases get the label patched.

Similar to:

• ci: add new release process using release-please auth#1391