tests

Update mypy requirement from ==1.14.* to >=1.14,<1.16 #6079

Job	Run time
collateral (diffcov)	4m 37s
test (3.9, ubuntu-latest)	4m 13s
collateral (docs)	2m 9s
test (3.9, macos-latest)	6m 40s
test_cygwin (39, windows-latest)	13m 25s
test (3.9, windows-latest)	10m 17s
test (3.13, ubuntu-latest)	4m 30s
test (3.13, macos-latest)	4m 12s
test (3.13, windows-latest)	12m 40s
test (3.10, ubuntu-latest)	4m 38s
test (3.11, ubuntu-latest)	4m 2s
test (3.12, ubuntu-latest)	5m 4s
test (3.14, ubuntu-latest)	6m 22s
test (pypy3.10, ubuntu-latest, stdlib)	17m 2s
test (ubuntu-latest, 3.10, stdlib)	4m 21s
integration-test	0s
check	2s
release	0s
	1h 44m 14s

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