added dependabot cooldown

Author: yseto

.github/dependabot.yml

@@ -3,7 +3,11 @@ updates:
 - package-ecosystem: bundler
   directory: "/"
   schedule:
-    interval: weekly
+    interval: daily
     time: "01:00"
     timezone: Asia/Tokyo
   open-pull-requests-limit: 10
+  cooldown:
+    default-days: 5
+    include:
+      - "*"