Roll src/third_party/libaom/source/libaom/ 27b123ff6..840f87978 (8 commits)

https://aomedia.googlesource.com/aom.git/+log/27b123ff6bd4..840f8797871c

$ git log 27b123ff6..840f87978 --date=short --first-parent --format='%ad %ae %s'
2024-10-09 wtc Avoid the use of aom_write_bit_buffer
2024-10-08 wtc Do not use aom_write_bit_buffer in write_av1config
2024-10-03 jzern fft.c: make some functions static
2024-10-03 jzern rm inv_wht_sse2.asm
2024-10-08 wtc Do not export aom_dsp_rtcd,aom_scale_rtcd,av1_rtcd
2024-10-08 marpan rtc: Reduce partition thresh_base for high motion
2024-10-09 maryla Fix type of previous_layer_frame_avail to avoid MSVC warning.
2024-10-03 maryla svc_encoder_rt: allow one input file per spatial layer

Created with:
  roll-dep src/third_party/libaom/source/libaom
R=jzern@google.com,eugene@chromium.org

Bug: b:307414544
Change-Id: Ib7059e77dbeffc5cc5745fd321c73372d9c97c34
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5924656
Reviewed-by: James Zern <jzern@google.com>
Commit-Queue: Wan-Teh Chang <wtc@google.com>
Auto-Submit: Wan-Teh Chang <wtc@google.com>
Commit-Queue: James Zern <jzern@google.com>
Cr-Commit-Position: refs/heads/main@{#1367241}