Keep Github Actions up-to-date with Dependabot (Gallopsled#2238)

Check every week if there are newer versions of the Github Actions we use.

Author: peace-maker

.github/dependabot.yml

@@ -0,0 +1,8 @@
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every week
+      interval: "weekly"