Upgrade symplify/easy-coding-standard package to 12.2

- rule files restructured to fit the new version
- ECS is now being run only in the main code base
- source: shopsys/shopsys#3192

Author: machacjan

.github/workflows/run-checks-tests.yaml

@@ -20,7 +20,3 @@ jobs:
                     tools: composer
             -   name: Install Composer dependencies
                 run: composer install --optimize-autoloader --no-interaction
-            -   name: Run parallel-lint
-                run: php vendor/bin/parallel-lint ./src
-            -   name: Run Easy Coding Standards
-                run: php vendor/bin/ecs check --verbose ./src

composer.json

@@ -22,13 +22,5 @@
     "require": {
         "php": "^8.3",
         "symfony/monolog-bridge": "^5.4.0"
-    },
-    "require-dev": {
-        "shopsys/coding-standards": "14.5.x-dev"
-    },
-    "config": {
-        "allow-plugins": {
-            "dealerdirect/phpcodesniffer-composer-installer": true
-        }
     }
 }