chore(gha): let dependabot know about the proxy

Author: paulbes

Diff for: .github/dependabot.yml

@@ -4,9 +4,19 @@
 # https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
 
 version: 2
+
+registries:
+  go-proxy:
+    type: go
+    url: https://riverqueue.com/goproxy
+    username: river
+    password: ${{ secrets.RIVER_PRO_SECRET }}
+
 updates:
   - package-ecosystem: "gomod"
     directory: "/"
+    registries:
+      - go-proxy
     schedule:
       interval: "weekly"
   - package-ecosystem: "docker"