tests

examples: fix multithreaded example callconv #407

Job	Run time
test_zig_nightly (ubuntu-24.04-arm)	24s
test_zig_nightly (ubuntu-latest)	2m 29s
test_cross (ubuntu-latest)	15s
test_cross (macos-latest)	25s
test_zig_nightly (windows-latest)	47s
test_cross (ubuntu-24.04-arm)	11s
test_zig_nightly (macos-latest)	44s
test_cross (windows-latest)	33s
	5m 48s

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