cmake: Add EXCLUDE_FROM_ALL to Linux install_headers

Even without it, we still need to run the following command for other
files:
`cmake --install . --component obs_libraries`

cmake/Modules/ObsHelpers_Linux.cmake

@@ -93,20 +93,23 @@ function(install_headers target)
       FILES
         "${CMAKE_CURRENT_SOURCE_DIR}/audio-monitoring/pulse/pulseaudio-wrapper.h"
       DESTINATION "${OBS_INCLUDE_DESTINATION}/audio-monitoring/pulse/"
-      COMPONENT obs_libraries)
+      COMPONENT obs_libraries
+      EXCLUDE_FROM_ALL)
   endif()
 
   if(ENABLE_HEVC)
     install(
       FILES "${CMAKE_CURRENT_SOURCE_DIR}/obs-hevc.h"
       DESTINATION "${OBS_INCLUDE_DESTINATION}"
-      COMPONENT obs_libraries)
+      COMPONENT obs_libraries
+      EXCLUDE_FROM_ALL)
   endif()
 
   if(NOT EXISTS "${OBS_INCLUDE_DESTINATION}/obsconfig.h")
     install(
       FILES "${CMAKE_BINARY_DIR}/config/obsconfig.h"
       DESTINATION "${OBS_INCLUDE_DESTINATION}"
-      COMPONENT obs_libraries)
+      COMPONENT obs_libraries
+      EXCLUDE_FROM_ALL)
   endif()
 endfunction()