CMake: `glfw/include` dirictory propagates not as SYSTEM include

Program build results in next include paths:
cl.exe /TP -IC:\<projpath>\src -IC:\<projpath>\deps\glfw\include -external:IC:\<projpath>\deps ...
-IC:\<projpath>\deps\glfw\include - not a system include (-I while must be -external:I)

Consider using target_include_directories(glfw SYSTEM PUBLIC **/include)

glfw/src/CMakeLists.txt

Lines 132 to 134 in bf945f1

    
           target_include_directories(glfw PUBLIC 
        
                                      "$<BUILD_INTERFACE:${GLFW_SOURCE_DIR}/include>" 
        
                                      "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")

Add SYSTEM: glfw PUBLIC -> glfw SYSTEM PUBLIC:
https://stackoverflow.com/a/61797712/11753532

The one more caveat is a need to conditionalize SYSTEM apply, so internal tests and/or examples builds will keep produce warnings

Looks like more of a CMake-wide issue coz every library is being setup this way.
Workaround is to add same or rooted include like:
fullpath: ${CMAKE_SOURCE_DIR}/deps/glfw/include

target_include_directories(${PROJECT_NAME} SYSTEM PRIVATE
  "${CMAKE_SOURCE_DIR}/deps" # all upper dirs will be treated as SYSTEM, even if opposite stated explicitly (with: -I)
)

If you install glfw in a particular directory and add the prefix to your other project, you'll get system headers by default for any library. CMake solved this but only for find_package.

	target_include_directories(glfw PUBLIC
	"$<BUILD_INTERFACE:${GLFW_SOURCE_DIR}/include>"
	"$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")