#153 deps-dev: bump stryker to 10.1.1

bump Stryker to 10.1.1, which works with vitest 5, and drop the vitest 4 install step from the mutation testing docs

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Summary by cubic

Bumps StrykerJS to 10.1.1, which supports vitest 5, and drops the temporary vitest@4 install step from the mutation testing workflow.