Check dependencies for released versions

Author: vmcj

.github/dependabot.yml

@@ -25,3 +25,12 @@ updates:
     allow:
         - dependency-type: "all"
     target-branch: "8.3"
+  - package-ecosystem: "composer"
+    directory: "/webapp"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 0
+    versioning-strategy: increase-if-necessary
+    allow:
+        - dependency-type: "all"
+    target-branch: "9.0"