.github: add dependabot

To perform automatic dependency and version updates.

Signed-off-by: Jiaqi Gao <[email protected]>

.github/dependabot.yml

@@ -0,0 +1,18 @@
+version: 2
+updates:
+
+  - package-ecosystem: "cargo"
+    directory: "/"
+    schedule:
+      # Check for updates to cargo dependencies every week
+      interval: "weekly"
+    open-pull-requests-limit: 1
+    allow:
+    - dependency-type: direct
+    - dependency-type: indirect
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every week
+      interval: "weekly"