glamor/xwayland: Define EGL_NO_X11

Define EGL_NO_X11 everywhere were we also define MESA_EGL_NO_X11_HEADERS,
EGL_NO_X11 is the MESA_EGL_NO_X11_HEADERS equivalent for the egl headers
shipped with libglvnd.

This fixes the xserver not building with the libglvnd-1.2.0 headers:

In file included from /usr/include/EGL/eglplatform.h:128,
                 from /usr/include/epoxy/egl_generated.h:11,
                 from /usr/include/epoxy/egl.h:46,
                 from glamor_priv.h:43,
                 from glamor_composite_glyphs.c:25:
/usr/include/X11/Xlib.h:222:2: error: conflicting types for 'GC'
  222 | *GC;
      |  ^~
In file included from glamor.h:34,
                 from glamor_priv.h:32,
                 from glamor_composite_glyphs.c:25:
../include/gcstruct.h:282:3: note: previous declaration of 'GC' was here
  282 | } GC;
      |   ^~

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
(cherry picked from commit 741bd734)
3 jobs for server-1.20-build-fixes in 5 minutes and 22 seconds (queued for 10 seconds)
Status Name Job ID Coverage
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passed debian-testing #887502

00:00:37

 
  Build And Test
passed autotools-build-and-test #887503

00:04:45

passed meson-build-and-test #887504

00:01:26