build: remove minimum-stability key and add @dev to phpcs.

We only need phpcs 4.0 to be minimum stability as `dev`, not all dependencies. So just remove the key and add `@dev` to the correct dependency version constraint.

Author: yCodeTech

composer.json

@@ -18,15 +18,14 @@
     ],
     "require": {
         "php": ">=7.2",
-        "squizlabs/php_codesniffer": "^3.13||^4.0",
+        "squizlabs/php_codesniffer": "^3.13||^4.0@dev",
         "dealerdirect/phpcodesniffer-composer-installer": "^1.1"
     },
     "require-dev": {
         "phpunit/phpunit": "^8.5||^9.6||^10.5||^11.5",
         "phpcsstandards/phpcsdevtools": "^1.0",
         "php-parallel-lint/php-parallel-lint": "^1.4"
     },
-    "minimum-stability": "dev",
     "autoload": {
         "psr-4": {
             "yCodeTech\\": "yCodeTech/"