Bump actions/checkout from 3 to 4 #2285

Job	Run time
Check Links	5m 34s
check_release	3m 39s
build (ubuntu-latest, 3.8)	5m 54s
build (ubuntu-latest, 3.11)	5m 43s
build (windows-latest, 3.8)	12m 34s
build (windows-latest, 3.11)	12m 37s
build (macos-latest, 3.8)	6m 54s
build (macos-latest, 3.11)	6m 38s
build (windows-latest, 3.9)	10m 35s
build (ubuntu-latest, pypy-3.8)	9m 1s
build (macos-latest, 3.10)	9m 19s
build (ubuntu-latest, 3.12)	8m 14s
integration_check (ubuntu-latest, 3.8)	2m 51s
integration_check (ubuntu-latest, 3.9)	2m 59s
integration_check (ubuntu-latest, 3.10)	2m 27s
integration_check (ubuntu-latest, 3.11)	2m 27s
integration_check_pypy	2m 23s
Make SDist	43s
Test Docs	1m 35s
Test Examples	57s
Test Lint	1m 59s
Test Minimum Versions	5m 14s
Test Prereleases	4m 16s
Install from SDist and Test	4m 0s
coverage	19s
tests_check	3s
	2h 8m 55s

Provide feedback