[cmake] fixes for XCode when having languages other than C/C++ (#3772)

Signed-off-by: lizzie <lizzie@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3772
Reviewed-by: crueter <crueter@eden-emu.dev>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

src/audio_core/CMakeLists.txt

@@ -222,10 +222,8 @@ if (MSVC)
     )
 else()
     target_compile_options(audio_core PRIVATE
-        -Werror=conversion
-
-        -Wno-sign-conversion
-    )
+        $<$<COMPILE_LANGUAGE:C,CXX>:-Werror=conversion>
+        $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-sign-conversion>)
 endif()
 
 target_include_directories(audio_core PRIVATE ${OPUS_INCLUDE_DIRS})