ci: Included githubactions in the dependabot config

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

dependency-update-tool:
https://github.com/ossf/scorecard/blob/main/docs/checks.md

Signed-off-by: Naveen <172697+naveensrinivasan@users.noreply.github.com>

.github/dependabot.yml

@@ -47,3 +47,13 @@ updates:
       - ci/skip/e2e
     commit-message:
       prefix: "rebase"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: weekly
+    rebase-strategy: disabled
+    labels:
+      - rebase
+      - ci/skip/e2e
+    commit-message:
+      prefix: rebase