Add a `rerun` option even if the test is successful

Hello 👋🏽 !

I wanted to check if you thought it would be interesting to add an option to `gotestsum` that would allow you to rerun a test even if it's not failing.
The idea is to rerun every new test several times to try and detect potential low-level flaky failures in advance.

If you find this useful, I can try to implement it.

Thanks in advance!

The issue names no files, tests, or entry points. Start by tracing how gotestsum exposes command-line options and invokes Go tests; define how successful tests should be selected and repeated, then verify that repeated runs can reveal a failure while preserving the existing result and output behavior.

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