switch to known-working syntax

Author: CleanCut

.github/dependabot.yaml

@@ -5,10 +5,10 @@ updates:
     directory: "/"
     schedule:
       interval: "cron"
-      cronjob: "0 5 8-14 * 0" # Second Sunday of each month at 05:00 UTC
+      cronjob: "0 5 2 * *" # Second day of each month at 05:00 UTC
 
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
       interval: "cron"
-      cronjob: "0 5 8-14 * 0" # Second Sunday of each month at 05:00 UTC
+      cronjob: "0 5 2 * *" # Second day of each month at 05:00 UTC