feat: add dependabot to shared workflows

.github/dependabot.yaml

@@ -0,0 +1,9 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+
+version: 2
+updates:
+- package-ecosystem: "github-actions" # See documentation for possible values
+  directory: "/.github/workflows" # Location of package manifests
+  schedule:
+    interval: "daily"