clang-tidy 16 fails in CI

[harakka]

Describe the bug

clang-tidy 16 fails in every CI run because FindSDL2_mixer.cmake can't find the flac dependency. This is probably caused by #68300 as it modified the tooling and tests started failing after it was merged.

Relevant error from an example full example here

-- Found SDL2_mixer: /usr/lib/x86_64-linux-gnu/libSDL2_mixer.so  
-- Searching for SDL_mixer deps libraries --
-- Checking for module 'flac'
--   No package 'flac' found
CMake Error at /usr/local/share/cmake-3.27/Modules/FindPkgConfig.cmake:607 (message):
  A required package was not found
Call Stack (most recent call first):
  /usr/local/share/cmake-3.27/Modules/FindPkgConfig.cmake:829 (_pkg_check_modules_internal)
  CMakeModules/Find/FindSDL2_mixer.cmake:115 (pkg_check_modules)
  CMakeLists.txt:334 (find_package)


-- Configuring incomplete, errors occurred!
Error: Process completed with exit code 1.

Attach save file

N/A

Steps to reproduce

Have a commit in a PR that triggers clang-tidy 16 run

Expected behavior

clang-tidy 16 setup to run successfully

Screenshots

No response

Versions and configuration

N/A

Additional context

No response

[harakka]

/confirm