Tweak Percy cron trigger to not run on weekends (#10519

`Runs at 04:17, Monday through Friday.`

Author: t3chguy

.github/workflows/element-web.yaml

@@ -4,7 +4,7 @@
 name: Element Web - Build
 on:
  schedule:
- - cron: "17 4 * * *" # every day at 04:17 UTC
+ - cron: "17 4 * * 1-5" # every weekday at 04:17 UTC
  pull_request: {}
  push:
  branches: [develop, master]