CI: Bump ci-templates dependency for working pip

wayland/ci-templates!18 allows the $HOME environment variable to
propagate into the execution of creating our build container. Without
that, buildah would leave us with an empty $HOME, which would have pip
install into /.local/bin.

As $HOME is preserved during our actual native builds, we would try to
find meson in /root/.local/bin and fail, since it had been stored to a
different path.

Bump the ci-templates dependency to one with the fix so we can build new
images again.

Signed-off-by: Daniel Stone <daniels@collabora.com>

.gitlab-ci.yml

@@ -11,7 +11,7 @@ variables:
 
 include:
   - project: 'wayland/ci-templates'
-    ref: b4b098a707c8f39d18f1a98d4bcbe65372ff9e17
+    ref: b7030c2cd0d6ccc5f6d4f8299bafa4daa9240d71
     file: '/templates/debian.yml'