tests

Update codecov/codecov-action to v4 #32

Job	Run time
test_cygwin (39, windows-latest)	22m 23s
collateral (diffcov)	6m 44s
test (3.8, ubuntu-latest)	6m 18s
collateral (docs)	1m 3s
test (3.8, macos-latest)	18m 35s
test (3.8, windows-latest)	14m 53s
test (3.11, ubuntu-latest)	4m 16s
test (3.11, macos-latest)	6m 32s
test (3.11, windows-latest)	11m 30s
test (3.12, ubuntu-latest)	6m 0s
test (3.12, macos-latest)	8m 48s
test (3.12, windows-latest)	11m 44s
test (3.9, ubuntu-latest)	6m 36s
test (3.10, ubuntu-latest)	3m 46s
test (pypy3.10, ubuntu-latest, stdlib)	6m 48s
test (ubuntu-latest, 3.10, stdlib)	4m 13s
integration-test	0s
check	3s
release	0s
	2h 20m 12s

Provide feedback