Doesn't compile with system's latest libchdr and doesn't use bundled

I was never able to compile this due to error with libchdr:

pcsx2/CDVD/ChdFileReader.cpp:56:24: error: no matching function for call to 'chd_open_file'
   56 |         const chd_error err = chd_open_file(*fp, mode, parent, chd);
      |                               ^~~~~~~~~~~~~
/usr/include/libchdr/chd.h:379:22: note: candidate function not viable: cannot convert argument of incomplete type 'RFILE *' to 'FILE *' (aka '_IO_FILE *') for 1st argument
  379 | CHD_EXPORT chd_error chd_open_file(FILE *file, int mode, chd_file *parent, chd_file **chd);
      |                      ^             ~~~~~~~~~~

This doesn't like includes from system's libchdr but does not seem to even attempt to use bundled 3rdparty/chdr/libchdr.
Even though cmake/SearchForStuff.cmake has add_subdirectory(3rdparty/chdr EXCLUDE_FROM_ALL) and 3rdparty/chdr/CMakeLists.txt has target_include_directories(chdr-static PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/libchdr/include"…, those includes are never used, it seems.

And I can't use precompiled version because libretro/retroarch inexplicably decided to hardcode all cores to AVX2, cutting off the most popular x86 platform: LGA2011 CPUs. Apparently, 12-core server AVX1-only processors aren't enough for those, even though it's what I use for playing pcsx2, rpcs3, dolphin at 4K/HDR10+. And Cyberpunk at native 1440p. Not for libretro though.

Start with pcsx2/CDVD/ChdFileReader.cpp and inspect dependency and include handling in cmake/SearchForStuff.cmake and 3rdparty/chdr/CMakeLists.txt. Trace which libchdr headers and target are selected during configuration, then verify a clean build uses the bundled library or supports the system version without the reported chd_open_file mismatch.