Add prereleases Ionic branches

[azeey]

Enable prereleases in all Ionic branches (some main and some with stable ranches like gz-cmake4). The goal is to be able to use prereleases for the tutorial party but still keep nightlies to expedite iterating on existing PRs.

[azeey]

I had to make the docopt changes to fix linting issues. pyright change behavior in handling the __doc__ parameter. From https://github.com/microsoft/pyright/releases/tag/1.1.372:

Changed the type of the doc attribute for a module to always be str | None. Previously, pyright changed its declared type to str if a docstring was present in the module, but this is incorrect because it's a writable value and can be set to None.

[scpeters]

this looks ok; should we test it with ci_matching_branch/?

[scpeters]

thanks for testing in gazebosim/gz-utils#137 !