Update Dependabot configuration for cargo packages

- Changed the directory for the buster-cli package from "/packages/buster-cli" to "/cli".
- Added a new configuration for the cargo package in the "/api" directory.
- Updated scheduling and branch settings for both packages to improve dependency management.

These changes streamline the dependency update process and enhance the organization of package configurations.

.github/dependabot.yml

@@ -1,11 +1,25 @@
 version: 2
 updates:
   - package-ecosystem: "cargo"
-    directory: "/packages/buster-cli"
+    directory: "/cli"
     schedule:
       interval: "weekly"
+    source-branch: "main"
+    target-branch: "staging"
+    open-pull-requests-limit: 10
+    labels:
+      - "dependencies"
+    commit-message:
+      prefix: "chore"
+      include: "scope"
+
+  - package-ecosystem: "cargo"
+    directory: "/api"
+    schedule:
+      interval: "weekly"
+    source-branch: "main"
+    target-branch: "staging"
     open-pull-requests-limit: 10
-    target-branch: "main"
     labels:
       - "dependencies"
     commit-message: