fix: add a new workflow for release candidates

[github-actions]

This is the main issue tracking #93

Please add labels indicating the release versions eg. 'release/v0'

Please add comments for user issues which this issue addresses.

Description copied from PR:

Related Issue

Addresses #5

Description

Automatically generate release candidates every time there is a merge to a release branch.

Testing

actionlint

Not a breaking change.

[matttrach]

merged