Re-activate pre-commit checks

[lang-m]

Temporarily disabled because they keep failing with an error that does not make sense (complaining about re-definition of a function that is not actually re-defined). Looks a bit like there was some sort of caching/lack of cache cleaning going on so that we end up with a mixture of different versions of one file when running the pre-commit checks.

@samjrholt and I individually had a look and both tested it locally. There does not seem to be a problem in the code and the pre-commits pass locally.

I hope that maybe disabling and re-enabling later might "magically" fix the problem.

[lang-m]

Done