maintain: add dependabot for this project

Author: shunsock

.github/dependabot.yml

@@ -0,0 +1,10 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+  - package-ecosystem: "gomod"
+    directory: "worker"
+    schedule:
+      interval: "monthly"

.github/workflows/go.yml

@@ -17,7 +17,7 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Set up Go
-      uses: actions/setup-go@v4
+      uses: actions/setup-go@v5
       with:
         go-version: '1.22'