Merge pull request #1129 from WyriHaximus/renovate/phpunit

Update dependency infection/infection to ^0.31.9

Author: WyriHaximus

composer.json

@@ -17,7 +17,7 @@
  "ergebnis/composer-normalize": "^2.48.2",
  "ergebnis/phpunit-slow-test-detector": "^2.20.0",
  "icanhazstring/composer-unused": "^0.9.5",
- "infection/infection": "^0.31.8",
+ "infection/infection": "^0.31.9",
  "maglnet/composer-require-checker": "^4.16.1",
  "mockery/mockery": "^1.6.12",
  "php-parallel-lint/php-console-highlighter": "^1.0",