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fuzz: Abort when using global PRNG without re-seed

Placeholder github Source User requested to merge github/fork/maflcko/2412-fuzz-rng-abort into master

This is the first step toward improving fuzz stability and determinism (https://github.com/bitcoin/bitcoin/issues/29018).

A fuzz target using the global test-only PRNG will now abort if the seed is re-used across fuzz inputs.

Also, temporarily add SeedRandomStateForTest(SeedRand::ZEROS) to all affected fuzz targets. This may slow down the libfuzzer leak detector, but it will disable itself after some time, or it can be disabled explicitly with -detect_leaks=0.

In a follow-up, each affected fuzz target can be stripped of the global random use and a local RandomMixin (or similar) can be added instead.

(Can be tested by removing any one of the re-seed calls and observing a fuzz abort)

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