Update phpstan/phpstan requirement from 1.10.50 to 1.10.60 (#152)

Updates the requirements on [phpstan/phpstan](https://github.com/phpstan/phpstan) to permit the latest version.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Changelog](https://github.com/phpstan/phpstan/blob/1.11.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@1.10.50...1.10.60)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

composer.json

@@ -31,7 +31,7 @@
         "phpunit/phpunit": "^9.6.13",
         "symfony/phpunit-bridge": "^7.0",
         "facile-it/facile-coding-standard": "1.2.0",
-        "phpstan/phpstan": "1.10.50",
+        "phpstan/phpstan": "1.10.60",
         "phpstan/extension-installer": "1.3.1",
         "jangregor/phpstan-prophecy": "1.0.0",
         "phpspec/prophecy": "^1.17",