CI: Build our own Pango instead of using msys

1. Msys builds it for fontconfig, we want DirectWrite

2. The testsuite needs fixes that only exist in master

3. We don't want to bump the required Pango version just for that

We should revert this when those fixes have landed upstream.

.gitlab-ci/test-msys2.sh

@@ -23,7 +23,6 @@ pacman --noconfirm -S --needed \
     ${MINGW_PACKAGE_PREFIX}-graphene \
     ${MINGW_PACKAGE_PREFIX}-json-glib \
     ${MINGW_PACKAGE_PREFIX}-libepoxy \
-    ${MINGW_PACKAGE_PREFIX}-pango \
     ${MINGW_PACKAGE_PREFIX}-fribidi \
     ${MINGW_PACKAGE_PREFIX}-gst-plugins-bad-libs \
     ${MINGW_PACKAGE_PREFIX}-shared-mime-info \
@@ -41,6 +40,7 @@ ccache --zero-stats
 ccache --show-stats
 export CCACHE_DISABLE=true
 meson setup \
+    --force-fallback-for pango \
     -Dx11-backend=false \
     -Dwayland-backend=false \
     -Dwin32-backend=true \