gitlab-ci: Disable sourcery

The sourcery plugin fails again due to a missing login. Disable it for
now.

.gitlab-ci.yml

@@ -70,10 +70,10 @@ script_limit:
         --key before_script
         --key after_script
 
-sourcery:
-  extends: .analyze
-  script:
-    - sourcery review --check --verbose scripts/*.py
+# sourcery:
+#   extends: .analyze
+#   script:
+#     - sourcery review --check --verbose scripts/*.py
 
 yamllint:
   extends: .analyze