Dependabot: Check hermit-builtins

.github/dependabot.yml

@@ -10,6 +10,14 @@ updates:
     # Automatic rebases cancel pending bors merges
     rebase-strategy: "disabled"
 
+  - package-ecosystem: "cargo"
+    directory: "/hermit-builtins"
+    schedule:
+      interval: "weekly"
+      timezone: "Europe/Berlin"
+    # Automatic rebases cancel pending bors merges
+    rebase-strategy: "disabled"
+
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule: