chore: Included githubactions in the dependabot config (#15985)

This should help with keeping the GitHub actions updated on new releases. This will also help with keeping it secure.

Dependabot helps in keeping the supply chain secure https://docs.github.com/en/code-security/dependabot

GitHub actions up to date https://docs.github.com/en/code-security/dependabot/working-with-dependabot/keeping-your-actions-up-to-date-with-dependabot

https://github.com/ossf/scorecard/blob/main/docs/checks.md#dependency-update-tool
Signed-off-by: naveen <172697+naveensrinivasan@users.noreply.github.com>

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"