Make our own mock kernel methods async #3006

Job	Run time
build (ubuntu-latest, 3.9)	2m 53s
check_release	1m 44s
link_check	3m 52s
build (ubuntu-latest, 3.13)	3m 9s
build (windows-latest, 3.9)	6m 46s
Make SDist	34s
build (windows-latest, 3.13)	8m 59s
build (macos-latest, 3.9)	5m 24s
test_docs	32s
build (macos-latest, 3.13)	5m 8s
build (ubuntu-latest, pypy-3.9)	4m 10s
Test Lint	1m 3s
build (macos-latest, 3.10)	4m 59s
Test Minimum Versions	2m 13s
build (ubuntu-latest, 3.11)	2m 48s
Test Prereleases	2m 0s
build (ubuntu-latest, 3.12)	3m 10s
test_without_debugpy (ubuntu-latest, 3.9)	1m 53s
Install from SDist and Test	1m 54s
coverage	13s
	1h 3m 24s

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