fix: larastan v1 incompatible with phpstan v1.9.0 (#3665)

We can't update to larastan v2 until we update to laravel v9 which has to wait for Flarum v2, so we need to stay on phpstan v1.8

Signed-off-by: Sami Mazouz <[email protected]>

composer.json

@@ -4,7 +4,7 @@
     "minimum-stability": "dev",
     "license": "MIT",
     "require": {
-        "phpstan/phpstan": "^1.2",
+        "phpstan/phpstan": ">=1.8.11 < 1.9.0",
         "nunomaduro/larastan": "^1.0"
     },
     "autoload": {