Update phpstan/extension-installer requirement from ^1.2 to ^1.4 (#161)

Author: dependabot[bot]

composer.json

@@ -17,7 +17,7 @@
         "thecodingmachine/safe": "^1.3 || ^2.0"
     },
     "require-dev": {
-        "phpstan/extension-installer": "^1.2",
+        "phpstan/extension-installer": "^1.4",
         "phpstan/phpstan": "^1.9",
         "phpunit/phpunit": "^9.6",
         "symfony/var-dumper": "^5.3",