action: check contrib/ gomod as well

Signed-off-by: Date Huang <tjjh89017@hotmail.com>

Author: tjjh89017

.github/dependabot.yml

@@ -10,3 +10,8 @@ updates:
     schedule:
       interval: "weekly"
 
+  - package-ecosystem: "gomod" # See documentation for possible values
+    directory: "/contrib/cloudflare" # Location of package manifests
+    schedule:
+      interval: "weekly"
+