Tests

ci: also test against jdk 21 #363

Job	Run time
test-ubuntu-graalvm-native	1m 49s
test-ubuntu-temurin@8	33s
test-windows-temurin@8	1m 8s
test-ubuntu-temurin@11	37s
test-ubuntu-graalvm-community-native	1m 14s
test-macOS-temurin@11	56s
test-macOS-graalvm-native	1m 55s
test-windows-temurin@11	1m 10s
test-macOS-graalvm-community-native	1m 18s
test-ubuntu-temurin@17	33s
test-windows-graalvm-native	3m 5s
test-macOS-temurin@17	54s
test-windows-graalvm-community-native	2m 10s
test-windows-temurin@17	1m 10s
test-ubuntu-temurin@21	35s
test-macOS-temurin@21	55s
test-windows-temurin@21	1m 29s
	21m 31s

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