Update to latest htscodecs

[daviesrob]

• Name tokeniser fixes.
• Fix tok3 decode bounds checking.
• Fix rans_set_cpu to work a second time.
• Bug fix the -c option for testing codecs.
• Bug fix the tests/entropy PACK+RLE+SIMD.
• Add round-trip fuzzer for entropy codecs (rANS, arithmetic)
• Add fuzzers to .gitignore
• Add a tok3 and fqzcomp round-trip fuzzer
• Replace SIMD gather with simulated gathers.
• Speed up rans_F_to_s3 function.
• AVX2 rans32x16 O1 speed up.
• AVX512 rans32x16 O1 speed up.
• Speed up AVX2 O1 encoder.
• Fix mem bounds checking in rans_uncompress_O0_32x16_avx2.
• Replace _mm512_i32gather_epi32(mm512, array, 1) with simulated gather.
• Fix the previous rans_set_cpu code to work with AVX2/AVX512 checks.
• Fix O1 AVX512 encoder.
• Minor improvement to -DENC_DEBUG diagnostics in name tokeniser.
• Fix tok3 encoding bug with duplicated streams.
• Remove undefined behaviour in transpose_and_copy.
• Add explicit -mpopcnt to avx2 and avx512 builds.
• Allow builds on old gcc's that don't like declarations in for loops