update some action versions, including upload-artifact & download-art…

…ifact which will be deprecated. Adds dependabot to update actions

.github/dependabot.yml

@@ -0,0 +1,9 @@
+---
+version: 2
+updates:
+# Set update schedule for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every week
+      interval: "weekly"