CI: configure Dependabot to monitor GitHub actions.

cpu · djc · commit cf50a4da5bd5 · 2023-03-14T22:21:53.000+01:00
This commit updates the existing `.github/dependabot.yml` config that
monitors Cargo dependencies to also monitor GitHub actions (on a weekly
cadence).
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
@@ -5,3 +5,7 @@ updates:
   schedule:
     interval: daily
   open-pull-requests-limit: 10
+- package-ecosystem: github-actions
+  directory: "/"
+  schedule:
+    interval: weekly
