Update dependabot.yml

Author: glennawatson

.github/dependabot.yml

@@ -3,11 +3,11 @@ updates:
 - package-ecosystem: nuget
   directory: "/"
   schedule:
-    interval: daily
+    interval: monthly
     time: "00:00"
   open-pull-requests-limit: 20
 - package-ecosystem: "github-actions"
   directory: "/"
   schedule:
     # Check for updates to GitHub Actions every weekday
-    interval: "daily"  
+    interval: "monthly"