ci: Remove installed-tests job

Installed tests require access to the system prefix, and thus a
system-wide installation of Meson, which we don't have.

We're going to restore this job at a later date.

.gitlab-ci.yml

@@ -159,40 +159,6 @@ fedora-mingw64:
     - ./mingw64-meson.sh -Dintrospection=disabled -Dgraphene:introspection=disabled _build
     - ninja -C _build
 
-installed-tests:
-  extends: .build-fedora-default
-  stage: build
-  needs: []
-  variables:
-    EXTRA_MESON_FLAGS: "-Dinstall-tests=true"
-    G_TEST_ACCESSIBLE: 1
-  script:
-    - .gitlab-ci/show-info-linux.sh
-    - export PATH="$HOME/.local/bin:$PATH"
-    - pip3 install --user meson~=0.64
-    - meson subprojects download
-    - meson subprojects update --reset
-    - meson setup
-        --prefix="${CI_PROJECT_DIR}/_installed"
-        ${COMMON_MESON_FLAGS}
-        ${EXTRA_MESON_FLAGS}
-        ${BACKEND_FLAGS}
-        ${FEATURE_FLAGS}
-        _build
-    - meson compile -C _build
-    - meson install -C _build
-    - export LD_LIBRARY_PATH=${CI_PROJECT_DIR}/_install/lib64
-    - dbus-run-session xvfb-run -a -s "-screen 0 1024x768x24"
-            gnome-desktop-testing-runner
-                   --report-directory=_build/installed-tests-report/failed/
-                   --parallel=0
-                   --dirs "${CI_PROJECT_DIR}/_installed/share"
-                   gtk-4.0
-  artifacts:
-    paths:
-      - "_build/installed-tests-report/"
-
-
 .mingw-defaults:
   extends: .only-default
   stage: build