Revert "Introduce `g_fuzzing` global for fuzzing checks" #31189

Assume's should not be compiled in for production builds. #31093 broke that property of Assume.

Closes #31178

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CI will fail and we'll probably need to reconsider #31057 and #31073

It would be good to make it constexpr instead #31178 (comment) and use that to fix the issues. Happy to do it myself, but I think it should be part of one pull request. Otherwise you'll just switch one issue for another and a follow-up has to be created anyway.

I don't think the approach described in #31178 (comment) would fix the ci issues? If we make it a compile time option we'll see the timeouts in p2p_headers_presync for the macos and windows CI either way.

Yeah, I am saying that the fix should be a complete one, at least when it comes to the ./src directory. Otherwise it will have to be touched again. I am happy to submit a pull, or review one. But I think there have been enough issue and pull request threads about this topic and it would be good to wrap it up in at most one or two pulls.

I am happy to submit a pull

Yes please