tests

Fix mypy errors in tests #1222

Job	Run time
py-3.9 lib-6.1 windows-latest	2m 53s
py-3.9 lib-6.1 ubuntu-latest	5m 16s
py-3.9 lib-6.0 windows-latest	3m 47s
style	16s
py-3.9 lib-6.0 ubuntu-latest	4m 10s
package-source	21s
py-3.9 lib-5.1 windows-latest	2m 56s
py-3.9 lib-5.1 ubuntu-latest	5m 28s
py-pypy3.9 lib-6.1 ubuntu-latest	5m 29s
py-3.9 lib-6.1 macos-latest	5m 9s
package-wheel (macos-latest, arm64)	20m 42s
package-wheel (macos-latest, x86_64)	22m 37s
package-wheel (ubuntu-latest, aarch64)	2h 45m 16s
package-wheel (ubuntu-latest, i686)	17m 11s
package-wheel (ubuntu-latest, x86_64)	16m 17s
package-wheel (windows-latest, AMD64)	14m 16s
publish	51s
	4h 52m 55s

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