workflows: use v4 of actions/checkout #1510
push.yml
on: push
Java8-Linux
4m 12s
Java11-Linux
3m 47s
Java11-MacOS
5m 6s
Java11-Windows
3m 47s
Java17-MacOS
4m 50s
Java19-Linux
3m 40s
Java19-MacOS
5m 25s
Java20-Windows
4m 11s