Merge pull request #3207 from slimphp/dependabot/composer/phpstan/php…

…stan-tw-1.8

Update phpstan/phpstan requirement from ^1.7 to ^1.8

composer.json

@@ -64,7 +64,7 @@
         "nyholm/psr7-server": "^1.0",
         "phpspec/prophecy": "^1.15",
         "phpspec/prophecy-phpunit": "^2.0",
-        "phpstan/phpstan": "^1.7",
+        "phpstan/phpstan": "^1.8",
         "phpunit/phpunit": "^9.5",
         "slim/http": "^1.2",
         "slim/psr7": "^1.5",