I really don't know where I can get a game-ready build of the new version of this mod

I really don't know where I can get a game-ready build of the new version of this mod

You clone this repository and build it yourself.

You clone this repository and build it yourself.

Maybe I could build it, but what about others?

Can you use curse.maven as repository?
Second, check https://repo.cleanroommc.com/#/releases/zone/rong/mixinbooter

And if you mean snapshot build for newest commit, better write a GHA script with your clone repo.
Then let other download from that instead