ci: Disable building introspection when not needed

We can just save few cycles when the build-test doesn't require it.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3016>

.gitlab-ci.yml

@@ -286,6 +286,7 @@ build-without-opengl-and-glx@x86_64:
         -Dglx=false
         -Degl_device=true
         -Dwayland_eglstream=true
+        -Dintrospection=false
     - meson compile -C build
     - sudo meson install --no-rebuild -C build
   artifacts:
@@ -308,6 +309,7 @@ build-without-native-backend-and-wayland@x86_64:
         -Dxwayland=false
         -Dcore_tests=false
         -Dnative_tests=false
+        -Dintrospection=false
     - meson compile -C build
     - sudo meson install --no-rebuild -C build
   artifacts:
@@ -328,6 +330,7 @@ build-wayland-only@x86_64:
         -Dxwayland=false
         -Dcore_tests=false
         -Dnative_tests=false
+        -Dintrospection=false
     - meson compile -C build
     - sudo meson install --no-rebuild -C build
   artifacts: