Add "jangregor/phpstan-prophecy" dependency

Author: tyler36

composer.json

@@ -12,6 +12,7 @@
     "require": {
         "php": "^7.2.5|^8.0",
         "composer/xdebug-handler": "^1.1 || ^2.0.1 || ^3.0",
+        "jangregor/phpstan-prophecy": "^1.0",
         "jean85/pretty-package-versions": "^1.5.0 || ^2.0.1",
         "mglaman/phpstan-drupal": "^1.0.0",
         "nette/neon": "^3.1",