update psalm/plugin-phpunit requirement from ^0.18.4 to ^0.19.0 (via #128)

Author: dependabot[bot]

composer.json

@@ -27,7 +27,7 @@
         "allure-framework/allure-php-commons": "^2.3.1"
     },
     "require-dev": {
-        "psalm/plugin-phpunit": "^0.18.4",
+        "psalm/plugin-phpunit": "^0.19.0",
         "remorhaz/php-json-data": "^0.5.3",
         "remorhaz/php-json-path": "^0.7.7",
         "squizlabs/php_codesniffer": "^3.7.2",