Schedule dependabot to run Monday 8am Mountain Time (#14)

- Add explicit schedule timing: Monday at 14:00 UTC (8am MT)
- Ensures consistent weekly runs instead of varying based on manual triggers
- Applied to all package ecosystems in the project

Author: mraible

.github/dependabot.yml

@@ -5,7 +5,13 @@ updates:
       - "/functions/itsmhelper/"
     schedule:
       interval: "weekly"
+      day: "monday"
+      time: "14:00"
+      timezone: "UTC"
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "weekly"
+      day: "monday"
+      time: "14:00"
+      timezone: "UTC"