.gitlab-ci.yml: Update Windows image.

The old image produced errors like

```
Downloading zlib patch from
  https://wrapdb.mesonbuild.com/v2/zlib_1.2.11-5/get_patch
A fallback URL could be specified using patch_fallback_url key in the wrap file
WrapDB connection failed to
  https://wrapdb.mesonbuild.com/v2/zlib_1.2.11-5/get_patch
with error
  <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify
   failed: certificate has expired (_ssl.c:1122)>
```

.gitlab-ci.yml

@@ -9,7 +9,8 @@ variables:
 .build windows common:
   # See
   # https://gitlab.freedesktop.org/gstreamer/gst-ci/container_registry/213
-  image: 'registry.freedesktop.org/gstreamer/gst-ci/amd64/windows:v14-master'
+  # https://lists.nongnu.org/archive/html/freetype-devel/2022-01/msg00004.html
+  image: 'registry.freedesktop.org/gstreamer/gst-ci/amd64/windows:v14-master:2021-09-09.0-master'
   stage: 'build'
   tags:
     - 'docker'