Add dependabot configuration for terraform

Author: whi-tw

.github/dependabot.yml

@@ -30,3 +30,14 @@ updates:
       schedule:
         interval: "daily"
       open-pull-requests-limit: 10
+
+    - package-ecosystem: terraform
+      directory: "/infra/shared"
+      schedule:
+        interval: weekly
+      open-pull-requests-limit: 10
+      groups:
+        terraform-all-dependencies:
+          patterns:
+            - "*"
+      target-branch: main