Move __version__ single source of truth to package __init__

[Erotemic]

Currently the main Python module don't have a __version__ property. This is a pseudo-standard property that many packages do include, and its helpful to have. I find putting __version__ in the top-level __init__.py is a good place for the single-source-of-truth for the version number. I've included code in the setup.py to parse that information from __init__.py file, so when versions change, you only need to bump the version in one place.

[oddstr13]

This is a lot of code for something rather simple – I tend to handle this with a simple regex in my own projects

https://github.com/oddstr13/jellyfin-plugin-repository-manager/blob/493e3aec37da39f8faa7a2ee308109edebe856b4/setup.py#L6-L7

with open('jprm/__init__.py', 'r') as fh:
    version = re.search(r'__version__ *= *["\'](.*?)["\']', fh.read()).group(1)

In jprm I also have CI to automate the version change as part of the release prep, but I see that this repo doesn't have anything of that sort yet. https://github.com/oddstr13/jellyfin-plugin-repository-manager/blob/493e3aec37da39f8faa7a2ee308109edebe856b4/.github/workflows/release-next-create-pr.yaml#L61-L69

[Erotemic]

Whatever the maintainers feel comfortable with is fine. The main thing I care about is that __version__ is defined.

This code is generated by my xcookie repo templater. While it is longer than a regex, this code correctly handles edge cases that the regex doesn't. I like things that treat code as code, but that's my opinion.

[iwalton3]

I usually just throw the version in the natural places and use a script to yell at me if I forget to change them all.

https://github.com/jellyfin/jellyfin-mpv-shim/blob/9d2d2b83e84b297c36a1d35634569a0269c485a7/gen_pkg.sh#L67-L87

[iwalton3]

I'd accept this PR if it just throws the version into the two places. I could add something like gen_pkg.sh myself.

[Erotemic]

I think it's important to have a single-source-of-truth for information like the version. It looks like the new pyproject.toml configuration has built in support for this sort of versioning. I think a better solution would be to switch to that.

[Erotemic]

I've added a commit that makes this change. This removes the problem of there being a lot of code in the setup.py. In fact there is no more code in the setup.py, the entire build process is now declarative. I build a wheel before / after this change to ensure that all metadata in the .whl/METADATA is preserved. (Note: author name is now included in the author email field using a git-like name <email> format).

[iwalton3]

Sure, this looks fine.