Fix build errors in static-compat-qt6-wayland

These build errors are caused because eglplatform.h is included before Qt
headers and it pulls X11 headers which contain many problematic macros.

Apparently X11 headers aren't required here anyways so let's just disable
them from being pulled in.

qt6-wayland/static-compat/PKGBUILD

@@ -26,6 +26,7 @@ build() {
   export PATH=$PWD:$PATH
   printf '#!/usr/bin/bash\nexec /usr/bin/pkg-config --static "$@"\n' > pkg-config
   chmod +x pkg-config
+  export CXXFLAGS+=' -DQT_EGL_NO_X11'
   static-compat-cmake -G Ninja -B build -S $_pkgfqn \
     $ccache_args \
     -DCMAKE_SKIP_INSTALL_RPATH=ON \

qt6-wayland/static-compat/PKGBUILD.sh.ep

@@ -9,3 +9,6 @@ license=(GPL3 LGPL3 FDL custom)
 pkgdesc='Provides APIs for Wayland'
 depends=(<%== qt6deps qw(declarative) %> static-compat-libxcomposite)
 makedepends=(static-compat-cmake static-compat-vulkan-headers ninja)
+% content_for before_build_config => begin
+  export CXXFLAGS+=' -DQT_EGL_NO_X11'
+% end