fix: dev: Add dependabot schedule for the dev container.

.github/dependabot.yml

@@ -1,9 +1,16 @@
 ---
-# Set update schedule for GitHub Actions
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for more information:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+# https://containers.dev/guide/dependabot
 
 version: 2
 updates:
-
+  - package-ecosystem: "devcontainers"
+    directory: "/"
+    schedule:
+      interval: weekly
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule: