Bump eclipsecbi/fedora-gtk3-mutter in /container

Bumps eclipsecbi/fedora-gtk3-mutter from `0dd65d2` to `688a66d`.

---
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:40-gtk3.24@sha256:0dd65d2841bbe9c08333e94e76f33313ef62c2ac9510d05ada6a3a0afb45017a
+FROM eclipsecbi/fedora-gtk3-mutter:40-gtk3.24@sha256:688a66d1cdcd3c1c383bf4ccf10e8e0d81d73c754901270b41cf4aafdc6b03f9
 
 # Back to root for install
 USER 0