Bump actions/checkout from 3 to 4 #1436

Job	Run time
Retro-compatibility (3.10, windows-latest, 232)	25m 49s
Retro-compatibility (3.10, windows-latest, 231)	12m 36s
Retro-compatibility (3.10, windows-latest, 222)	10m 20s
Retro-compatibility (3.10, windows-latest, 221)	12m 41s
Retro-compatibility (3.10, ubuntu-latest, 232)	16m 41s
Retro-compatibility (3.10, ubuntu-latest, 231)	12m 14s
Retro-compatibility (3.10, ubuntu-latest, 222)	10m 5s
Retro-compatibility (3.10, ubuntu-latest, 221)	10m 49s
debug	1s
Style Check	1m 6s
tests (3.8, windows-latest)	17m 45s
tests (3.8, ubuntu-latest)	12m 51s
tests (3.9, windows-latest)	15m 42s
tests (3.9, ubuntu-latest)	13m 45s
tests (3.10, windows-latest)	15m 47s
tests (3.10, ubuntu-latest)	6h 0m 17s
docs / Documentation	19m 39s
examples / Setup	3s
docs / Check doc style / Documentation Style Check	52s
examples / Run Examples (3.10, windows-latest)	20m 12s
examples / Run Examples (3.10, ubuntu-latest)	9m 16s
upload-development-docs	0s
	9h 58m 31s

Provide feedback