chore: Update dependabot.yml (#1814)

* chore: Update dependabot.yml

Author: ddixit14

synthtool/gcp/templates/java_library/.github/dependabot.yml

@@ -6,12 +6,14 @@ updates:
       interval: "daily"
     # Disable version updates for Maven dependencies
     # we use renovate-bot as well as shared-dependencies BOM to update maven dependencies.
-    ignore: "*"
+    ignore:
+      - dependency-name: "*"
   - package-ecosystem: "pip"
     directory: "/"
     schedule:
       interval: "daily"
     # Disable version updates for pip dependencies
     # If a security vulnerability comes in, we will be notified about 
     # it via template in the synthtool repository.
-    ignore: "*"
+    ignore:
+      - dependency-name: "*"