Update phpstan/extension-installer requirement from ^1.1.0 to ^1.2.0

Updates the requirements on [phpstan/extension-installer](https://github.com/phpstan/extension-installer) to permit the latest version.
- [Release notes](https://github.com/phpstan/extension-installer/releases)
- [Commits](phpstan/extension-installer@1.1.0...1.2.0)

---
updated-dependencies:
- dependency-name: phpstan/extension-installer
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

composer.json

@@ -32,7 +32,7 @@
     "require-dev": {
         "jangregor/phpstan-prophecy": "^1.0.0",
         "phpspec/prophecy-phpunit": "^2.0",
-        "phpstan/extension-installer": "^1.1.0",
+        "phpstan/extension-installer": "^1.2.0",
         "phpstan/phpstan": "^1.8",
         "phpunit/phpunit": "^9.5.26",
         "squizlabs/php_codesniffer": "^3.7"