add PHPStan package (mongodb#1930)

Author: Treggats

composer.json

@@ -35,7 +35,8 @@
         "orchestra/testbench": "^8.0",
         "mockery/mockery": "^1.4.4",
         "doctrine/coding-standard": "12.0.x-dev",
-        "spatie/laravel-query-builder": "^5.6"
+        "spatie/laravel-query-builder": "^5.6",
+        "phpstan/phpstan": "^1.10"
     },
     "replace": {
         "jenssegers/mongodb": "self.version"