Update phpstan/phpstan requirement from ^1.9 to ^1.10 (#27)

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/1.10.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@1.9.0...1.10.3)

---
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

@@ -45,7 +45,7 @@
     "require-dev": {
         "phpunit/phpunit": "^9",
         "squizlabs/php_codesniffer": "^3.7",
-        "phpstan/phpstan": "^1.9"
+        "phpstan/phpstan": "^1.10"
     },
     "autoload-dev": {
         "psr-4": {