[TASK] Update symplify/easy-coding-standard requirement

Updates the requirements on [symplify/easy-coding-standard](https://github.com/easy-coding-standard/easy-coding-standard) to permit the latest version.
- [Release notes](https://github.com/easy-coding-standard/easy-coding-standard/releases)
- [Commits](easy-coding-standard/easy-coding-standard@12.5.0...12.6.0)

---
updated-dependencies:
- dependency-name: symplify/easy-coding-standard
  dependency-version: 12.6.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

composer.json

@@ -19,7 +19,7 @@
         "ergebnis/composer-normalize": "^2.48",
         "phpstan/phpstan": "^1.12",
         "ssch/typo3-rector": "^2.12",
-        "symplify/easy-coding-standard": "^12.5",
+        "symplify/easy-coding-standard": "^12.6",
         "typo3/cms-backend": "^13.4",
         "typo3/cms-frontend": "^13.4"
     },