CI: Disable Windows again

We thought HTTP was stable after nginx changes, but sadly it isn't.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6495>

.gitlab-ci.yml

@@ -382,7 +382,7 @@ arm64_test:
     WINDOWS_IMAGE: "$CI_REGISTRY_IMAGE/windows/x64_build:$WINDOWS_TAG"
     WINDOWS_UPSTREAM_IMAGE: "$CI_REGISTRY/$FDO_UPSTREAM_REPO/windows/x64_build:$WINDOWS_TAG"
 
-windows_build_vs2019:
+.windows_build_vs2019:
   extends:
     - .container
     - .windows-docker-vs2019
@@ -684,7 +684,7 @@ meson-clang:
     CC: "ccache clang-9"
     CXX: "ccache clang++-9"
 
-meson-windows-vs2019:
+.meson-windows-vs2019:
   extends:
     - .build-windows
     - .use-windows_build_vs2019