Revert "XorgPackage, glx: conflicts windows and darwin (#50216)" (#50231)

This reverts commit 382847976f.

lib/spack/spack/build_systems/xorg.py

@@ -6,17 +6,12 @@
 
 import spack.package_base
 import spack.util.url
-from spack.directives import conflicts
 
 
 class XorgPackage(spack.package_base.PackageBase):
     """Mixin that takes care of setting url and mirrors for x.org
     packages."""
 
-    # x.org packages are not supported on windows or darwin
-    conflicts("platform=windows")
-    conflicts("platform=darwin")
-
     #: Path of the package in a x.org mirror
     xorg_mirror_path: Optional[str] = None
 

var/spack/repos/builtin/packages/glx/package.py

@@ -12,9 +12,6 @@ class Glx(BundlePackage):
 
     version("1.4")
 
-    conflicts("platform=windows")
-    conflicts("platform=darwin")
-
     depends_on("libglx")
     provides("gl@4.5")