libaom v3.9.1 release candidate 2

[Wan-Teh Chang]

Hi everyone,

libaom v3.9.1 release candidate 2 is available. The release tag is
v3.9.1-rc2. Your testing will be greatly appreciated.

This release includes several bug fixes. This release is ABI
compatible with the last release. See
https://aomedia.googlesource.com/aom/+log/v3.9.0..v3.9.1-rc2 for all the
commits in this release.

- Bug Fixes
* aomedia:2754, aomedia:3567: Ensure thread stack size is at least
256 KB
* b:330639949, oss-fuzz:68195: Increase scaling in linsolve_wiener
* Fix high target data rate overflow.
* aomedia:3509: Fix two UBSan errors in av1_rc_update_framerate()
* aomedia:3382, chromium:339877165: update codec config after
svc/scale controls (CVE-2024-5493)
* aomedia:3561: libaom-3.8.2 armv7 Android build failed
* aomedia:3571: {,highbd_}intrapred_neon.c: Avoid over-reads in z1
and z3 preds
* aomedia:3578: libaom-3.9.0 undefined reference to
`aom_sub_pixel_variance16xh_ssse3'
* aomedia:3579: Use round for RC calculations in cyclic_refresh
* aomedia:3580: Allow g_timebase.num to be greater than
g_timebase.den
* oss-fuzz:68774: libaom:av1_dec_fuzzer: Segv on unknown address in
od_ec_dec_init
* Arm SVE build fixes.
* av1_block_error_lp_neon: fix block_size param type
* av1_block_error_lp_sve: fix block_size param type

Thanks,
Wan-Teh Chang