Bump eclipsecbi/fedora-gtk3-mutter in /container

Bumps eclipsecbi/fedora-gtk3-mutter from `f827e3e` to `cb500df`.

---
updated-dependencies:
- dependency-name: eclipsecbi/fedora-gtk3-mutter
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

container/Dockerfile

@@ -1,4 +1,4 @@
-FROM eclipsecbi/fedora-gtk3-mutter:39-gtk3.24@sha256:f827e3ee8207c54a98298eeea3eb7bf2fc0de6e2e4c46c90779e8653dc541b69
+FROM eclipsecbi/fedora-gtk3-mutter:39-gtk3.24@sha256:cb500df887cc2d68188ae3b19b97fe47dd2b906624f0f5fdc38b1a2f5a03cb20
 
 # Back to root for install
 USER 0