test: kill escaped mutants to achieve MSI=100%

[Maks Rafalko (maks-rafalko)]

I would like to make a number of improvements for Infection in this repo, like

• achieve MSI=100%
• get rid of time outs; set maximum allowed time outs (more on this in separate PRs). Read here about why it matters: https://infection.github.io/2026/01/14/whats-new-in-0.32.3/#The-Problem
• run MT with PHPStan (we recently implemnted an integration to kill Mutants with Static Analysis tools): https://infection.github.io/guide/static-analysis-integration.html
• etc.

This PR kills outstanding escaped mutants and sets MSI to 100%, so now all the mutants must either be killed in the new code or ignored.