composer(deps-dev): bump phpstan/extension-installer from 1.1.0 to 1.2.0

Bumps [phpstan/extension-installer](https://github.com/phpstan/extension-installer) from 1.1.0 to 1.2.0.
- [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
  update-type: version-update:semver-minor
...

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

composer.json

@@ -38,7 +38,7 @@
     "ergebnis/php-cs-fixer-config": "^4.11.0",
     "ergebnis/phpstan-rules": "^1.0.0",
     "infection/infection": "~0.26.6",
-    "phpstan/extension-installer": "^1.1.0",
+    "phpstan/extension-installer": "^1.2.0",
     "phpstan/phpstan": "^1.6.2",
     "phpstan/phpstan-deprecation-rules": "^1.0.0",
     "phpstan/phpstan-doctrine": "^1.3.3",