FindGLUT: cmake 3.22.1 with PkgConf no longer sets GLUT_INCLUDE_DIR

Hi,

Since last cmake release on Archlinux, and I believe this merge request which introduced pkgconf usage in FindGLUT.cmake, GLUT_INCLUDE_DIR and GLUT_glut_LIBRARY are no longer set when pkgconf is found.

Instead, a GLUT_INCLUDEDIR is created and the path to glut.so can be found in GLUT_LINK_LIBRARIES.

Maybe the behaviour is wanted and the documentation just needs a small update ?

You can find attached a small Dockerfile and a basic CMakeLists.txt to play with. Dockerfile CMakeLists.txt

---

This are all the variables related to GLUT in the CMakeCache.txt

GLUT_CFLAGS:INTERNAL=
GLUT_CFLAGS_I:INTERNAL=
GLUT_CFLAGS_OTHER:INTERNAL=
GLUT_FOUND:INTERNAL=1
GLUT_INCLUDEDIR:INTERNAL=/usr/include
GLUT_INCLUDE_DIRS:INTERNAL=
GLUT_LDFLAGS:INTERNAL=-L/usr/lib;-lglut
GLUT_LDFLAGS_OTHER:INTERNAL=
GLUT_LIBDIR:INTERNAL=/usr/lib
GLUT_LIBRARIES:INTERNAL=glut
GLUT_LIBRARY_DIRS:INTERNAL=/usr/lib
GLUT_LIBS:INTERNAL=
GLUT_LIBS_L:INTERNAL=
GLUT_LIBS_OTHER:INTERNAL=
GLUT_LIBS_PATHS:INTERNAL=
GLUT_MODULE_NAME:INTERNAL=glut
GLUT_PREFIX:INTERNAL=/usr
GLUT_STATIC_CFLAGS:INTERNAL=
GLUT_STATIC_CFLAGS_I:INTERNAL=
GLUT_STATIC_CFLAGS_OTHER:INTERNAL=
GLUT_STATIC_INCLUDE_DIRS:INTERNAL=
GLUT_STATIC_LDFLAGS:INTERNAL=-L/usr/lib;-lglut;-lX11;-lXxf86vm;-lXrandr;-lGL;-lm
GLUT_STATIC_LDFLAGS_OTHER:INTERNAL=
GLUT_STATIC_LIBDIR:INTERNAL=
GLUT_STATIC_LIBRARIES:INTERNAL=glut;X11;Xxf86vm;Xrandr;GL;m
GLUT_STATIC_LIBRARY_DIRS:INTERNAL=/usr/lib
GLUT_STATIC_LIBS:INTERNAL=
GLUT_STATIC_LIBS_L:INTERNAL=
GLUT_STATIC_LIBS_OTHER:INTERNAL=
GLUT_STATIC_LIBS_PATHS:INTERNAL=
GLUT_VERSION:INTERNAL=3.2.1
GLUT_glut_INCLUDEDIR:INTERNAL=
GLUT_glut_LIBDIR:INTERNAL=
GLUT_glut_PREFIX:INTERNAL=
GLUT_glut_VERSION:INTERNAL=