Update dependency infection/infection to ^0.31.0

| datasource | package             | from   | to     |
| ---------- | ------------------- | ------ | ------ |
| packagist  | infection/infection | 0.30.3 | 0.31.0 |


Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

composer.json

@@ -33,7 +33,7 @@
     "ext-pdo_sqlite": "*",
     "doctrine/migrations": "^3.3.2",
     "doctrine/orm": "^2.19.4|^3.1.2",
-    "infection/infection": "^0.30.0",
+    "infection/infection": "^0.31.0",
     "league/commonmark": "^2.4",
     "patchlevel/coding-standard": "^1.3.0",
     "phpspec/prophecy-phpunit": "^2.1.0",