Add Dependabot config for GitHub Actions (#1265)

Upgrades GitHub Actions automatically

Author: tony-iqlusion

.github/dependabot.yml

@@ -1,8 +1,12 @@
 version: 2
 updates:
-- package-ecosystem: cargo
-  directory: "/"
-  schedule:
-    interval: daily
-    time: '13:00'
-  open-pull-requests-limit: 10
+  - package-ecosystem: cargo
+    directory: "/"
+    schedule:
+      interval: daily
+    open-pull-requests-limit: 10
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 10