It is definitely possible to have determinism in a CI build step, and it's possible to have checks for it. If one needs determinism and a cache, they can store the files on S3 or some other place instead of git. Re-generating the files every time on the build isn't the only alternative. Instead of generate-and-commit, generate and upload. The difficulty is the same for developers.
If one has to be more granular than that, and have versioning and verification against the repository, they can still store the multiple versions on another service and store the hashes on git. Even though I'm not a fan of this for translation (especially if you have lots of languages/lots of strings), since there's an advantage of decoupling the translation process from the development process.
The problem with storing those files on git is that it can cause more problems, including developer experience issues.
It depends on how much you're storing on git. Some CSS files? Fine. 70% of files of the project, like in this case, slowing down everyone's workflow? Definitely not.
If one has to be more granular than that, and have versioning and verification against the repository, they can still store the multiple versions on another service and store the hashes on git. Even though I'm not a fan of this for translation (especially if you have lots of languages/lots of strings), since there's an advantage of decoupling the translation process from the development process.
The problem with storing those files on git is that it can cause more problems, including developer experience issues.
It depends on how much you're storing on git. Some CSS files? Fine. 70% of files of the project, like in this case, slowing down everyone's workflow? Definitely not.