Merge pull request statsmodels#8499 from EwoutH/patch-3

Add Dependabot configuration for GitHub Actions updates

Author: bashtage

.github/dependabot.yml

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