v3.120.2

This minor release fixes a number of additional bugs related to the
thread queue, included demos, included helpers, and build system.

Changes:
- replace the `shaderc` library checks by pkg-config checks
- `pl_dispatch` no longer grows infinitely, but prunes stale cache
  entries after a certain threshold
- improve logging of GPU capabilities (including format capabilities)

Fixes and performance improvements:
- fix a typo on an error message
- fix a use-after-free edge case in `plplay`
- filter out Infinity, NaN and other values from fps/vps estimates
- add several warnings for suspected frame queue API misuses
- fix a crash when combining pl_render_image_mix with cropped frames
- fix a crash on AV_PIX_FMT_NONE in the libav helpers
- fix the loading of overlays in the `sdlimage` demo
- fix a number of potential overflows on 32-bit platforms
- omit redundant identity matrices in pl_shader_decode_color
- fix crash in frame queue with certain out-of-order PTS sequences
- add missing link to vulkan dependency in the `video-filtering` demo
- correctly shift overlays when drawing to subsampled YCbCr planes
- add missing check for PL_GPU_CAP_CALLBACKS in `utils/{libav,dav1d}.h`
- improve handling of asynchronous texture uploads in `utils/libav.h`
This tag has no release notes.