Preliminary setup for using github actions to build releases, run tests, etc.

[simcop2387]

I'll redo and squash this before actually saying it's ready, but here's a start of using github actions to create a pre-release based on current master branch.

• It needs some work to fix up the release name a bit so that it makes sense
• It should only run the release creation once, right now it'll run it for each OS in the matrix
• I don't think it's making a proper change log right now, should be fixable
• It doesn't try to create a normal release (i.e. non-preview) when making a tag
• It'd be nice if it also updated the repository when building a tagged version, so that jellyfin will pick it up automatically
• badges in readme still point to yt-dlp actions rather than this repo.

Those are the immediate things I see that are needed for this, let me know if you see any other issues with doing it this way

[simcop2387]

Also forgot to mention that it does run dotnet test, but they fail right now so it ignores the failure. That's something that should be addressed (either fixing the tests, the code, or i'm running them wrong)

[ankenyr]

Thanks for the commit, I changed that one line back since it is required as far as I can tell.