ci: Re-enable asan and ubsan for fuzz tests

[jouho]

Resolved issues:

Asan and ubsan were disabled for fuzz testing due to memory issues in CI after transitioning from the Make build system to CMake. These sanitizers are critical for detecting memory-related issues, and re-enabling them will enhance fuzz coverage.

Memory issue reproduced in this CodeBuild job

The likely cause of the memory issues was not disabling MADV_DONTDUMP as required, which is documented here:

s2n-tls/utils/s2n_mem.c

Lines 103 to 112 in 5a2fdf6

	/*
	** We disable MAD_DONTDUMP when fuzz-testing or using the address sanitizer because
	** both need to be able to dump pages to function. It's how they map heap output.
	*/
	#if defined(MADV_DONTDUMP) && !defined(S2N_ADDRESS_SANITIZER) && !defined(S2N_FUZZ_TESTING)
	if (madvise(*ptr, *allocated, MADV_DONTDUMP) != 0) {
	POSIX_GUARD(s2n_mem_free_no_mlock_impl(*ptr, *allocated));
	POSIX_BAIL(S2N_ERR_MADVISE);
	}
	#endif

This PR re-enables asan and ubsan for better test coverage.

Description of changes:

Add asan and ubsan option to fuzz tests, and add a compile definition for fuzz test to disable MAD_DONTDUMP

Testing:

• s2nFuzzBatch is running without exhausting its memory.
• successfully running scheduled fuzz batch for a reduced time (60 secs) against this change: Link to CodeBuild job

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.