Add dependabot cooldown (#1174)

Add a 3 day cooldown for dependabot updates.

Author: martincostello

.github/dependabot.yml

@@ -2,6 +2,8 @@ version: 2
 updates:
 - package-ecosystem: "github-actions"
   directory: "/"
+  cooldown:
+    default-days: 3
   groups:
     actions:
       patterns:
@@ -12,6 +14,8 @@ updates:
     timezone: Europe/London
 - package-ecosystem: nuget
   directory: "/"
+  cooldown:
+    default-days: 3
   schedule:
     interval: daily
     time: "06:30"

.github/zizmor.yml

@@ -1,6 +1,9 @@
 rules:
   anonymous-definition:
     disable: true
+  dependabot-cooldown:
+    config:
+      days: 3
   secrets-outside-env:
     disable: true
   undocumented-permissions: