mpv: reduce the build size a little

[kasper93]

An attempt to fix two issues:

• sporadic No space left on device during build check
• /usr/local/bin/compile: line 333: 11681 Killed python3 /fuzz-introspector/src/main.py report $REPORT_ARGS

Disabling FFmpeg filters is unfortunate, as it reduces coverage of filtering code, but lets focus on stabilizing the core code first.

Introspector fail is likely an OOM error, not sure if this commit will help with it.

Generally mpv is not that big project, so those failures are not expected, but lets try to workaround the limitations.

[github-actions[bot]]

kasper93 is either the primary contact or is in the CCs list of projects/mpv.
kasper93 has previously contributed to projects/mpv. The previous PR was #12081