Bump doctrine/coding-standard from 7.0.1 to 8.1.0

Bumps [doctrine/coding-standard](https://github.com/doctrine/coding-standard) from 7.0.1 to 8.1.0.
- [Release notes](https://github.com/doctrine/coding-standard/releases)
- [Commits](doctrine/coding-standard@7.0.1...8.1.0)

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

Author: dependabot-preview[bot]

composer.json

@@ -20,7 +20,7 @@
     "license": "MIT",
     "require": {
         "php": "^7.2",
-        "doctrine/coding-standard": "^7.0"
+        "doctrine/coding-standard": "^8.1"
     },
     "require-dev": {
         "roave/security-advisories": "dev-master"