contrib: aom: update to 3.8.1

2024-01-17 v3.8.1 This release includes several bug fixes. This release is ABI compatible with the last release. See https://aomedia.googlesource.com/aom/+log/v3.8.0..v3.8.1 for all the commits in this release.

• Bug Fixes
  • aomedia:3520: get_cubic_kernel_dbl: Assertion `0 <= x && x < 1' failed.
  • aomedia:3526: alloc_compressor_data() is called during every aom_codec_control() call on the encoder.
  • aomedia:3527: aom/av1/encoder/mcomp.c:1810: av1_full_pixel_search: Assertion `ms_params->ms_buffers.ref->width == ms_params->ms_buffers.src->width' failed.
  • aomedia:3534: libaom encoder crashed by AOM_USAGE_ALL_INTRA and AOM_EFLAG_NO_REF_LAST flags.
  • b/310455204: Recreate workers if necessary.
  • b/310548198: Update frame size in actual encoding.
  • b/314858909: Do not use adaptive error estimate.
  • Fix a hang of cmake on arm64 macOS with cmake 3.27.0 or later.