tests

Add news fragment. #6166

Job	Run time
test_cygwin (39, windows-latest)	18m 47s
test (3.9, ubuntu-latest)	4m 19s
collateral (diffcov)	4m 27s
test (3.9, macos-latest)	4m 32s
collateral (docs)	2m 8s
test (3.9, windows-latest)	11m 51s
test (3.13, ubuntu-latest)	4m 55s
test (3.13, macos-latest)	4m 19s
test (3.13, windows-latest)	12m 35s
test (3.10, ubuntu-latest)	4m 27s
test (3.11, ubuntu-latest)	4m 7s
test (3.12, ubuntu-latest)	5m 7s
test (3.14, ubuntu-latest)	8m 5s
test (pypy3.10, ubuntu-latest, stdlib)	16m 26s
test (ubuntu-latest, 3.10, stdlib)	4m 22s
integration-test	0s
check	2s
release	0s
	1h 50m 29s

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