Update slevomat/coding-standard requirement from ^7.0 to ^7.0 || ^8.0

Updates the requirements on [slevomat/coding-standard](https://github.com/slevomat/coding-standard) to permit the latest version.
- [Release notes](https://github.com/slevomat/coding-standard/releases)
- [Commits](slevomat/coding-standard@7.0.0...8.9.2)

---
updated-dependencies:
- dependency-name: slevomat/coding-standard
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -21,7 +21,7 @@
         "phpunit/phpunit": "^9.5",
         "psr/http-message": "^1.0 || ^2.0",
         "etsglobal/php-static-analysis": "^2.0",
-        "slevomat/coding-standard": "^7.0",
+        "slevomat/coding-standard": "^7.0 || ^8.0",
         "squizlabs/php_codesniffer": "^3.6",
         "symfony/phpunit-bridge": "^6.0",
         "symfony/http-client-contracts": "^3.0",