rusticl/gl: make GLX support optional

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26394>

meson.build

@@ -2015,6 +2015,9 @@ if with_platform_x11
     dep_xfixes = dependency('xfixes', version : '>= 2.0')
     dep_xcb_glx = dependency('xcb-glx', version : '>= 1.8.1')
     dep_xcb_shm = dependency('xcb-shm')
+  elif with_gallium_rusticl
+    # needed for GL sharing extension
+    dep_x11 = dependency('x11')
   endif
   if (with_any_vk or with_glx == 'dri' or with_egl or
        (with_gallium_vdpau or with_gallium_va or
@@ -2069,9 +2072,6 @@ if with_platform_x11
   if with_xlib_lease
     dep_xlib_xrandr = dependency('xrandr', version : '>= 1.3')
   endif
-elif with_gallium_rusticl
-  # needed for GL sharing extension
-  dep_x11 = dependency('x11')
 endif
 
 if with_dri