composer(deps-dev): bump phpstan/extension-installer from 1.0.5 to 1.1.0

Bumps [phpstan/extension-installer](https://github.com/phpstan/extension-installer) from 1.0.5 to 1.1.0.
- [Release notes](https://github.com/phpstan/extension-installer/releases)
- [Commits](phpstan/extension-installer@1.0.5...1.1.0)

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

composer.json

@@ -30,7 +30,7 @@
     "ergebnis/php-cs-fixer-config": "^2.10.0",
     "ergebnis/phpstan-rules": "~0.15.2",
     "ergebnis/test-util": "^1.4.0",
-    "phpstan/extension-installer": "^1.0.5",
+    "phpstan/extension-installer": "^1.1.0",
     "phpstan/phpstan": "~0.12.64",
     "phpstan/phpstan-deprecation-rules": "~0.12.6",
     "phpstan/phpstan-phpunit": "~0.12.17",