retroarch: update to 1.22.2

[jl4c]

Testing the changes

• I tested the changes in this PR: YES

Notes

RetroArch 1.22.2 updated libchdr with ZStandard support (see changelog:
https://raw.githubusercontent.com/libretro/RetroArch/master/CHANGES.md).
The new libchdr uses dr_flac (a header-only library from dr_libs) instead
of system libFLAC, breaking the build with --disable-builtinflac.

Changes:

• replaced --disable-builtinflac with --enable-builtinflac in configure_args
• removed flac build option (no longer meaningful)
• removed libflac-devel from makedepends

Arch Linux made the same change, dropping flac from depends in 1.22.2.

Local build testing

• I built this PR locally for my native architecture, x86_64-glibc

[Vinfall]

Although it's disabled by default, retroarch also supports building with qt6 since 1.20.0.

[jl4c]

Superseded by #60556, which includes a more thorough refactor and uses a patch to fix the FLAC build issue instead of disabling system libflac. Closing.