Reenable Dependabot for internal GitHub actions (#455)

* Reenable Dependabot for internal GitHub actions

* Apply suggestions from code review

Co-authored-by: Nara Kasbergen Kwon <855115+xiehan@users.noreply.github.com>

* Add label

---------

Co-authored-by: Nara Kasbergen Kwon <855115+xiehan@users.noreply.github.com>
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index eed0ba6..083d5d9 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -5,3 +5,20 @@
     schedule:
       interval: "daily"
     labels: ["dependencies"]
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+    labels:
+      - dependencies
+    # only update HashiCorp actions, external actions managed by TSCCR
+    allow:
+      - dependency-name: hashicorp/*
+    groups:
+      github-actions-breaking:
+        update-types:
+          - major
+      github-actions-backward-compatible:
+        update-types:
+          - minor
+          - patch