Update wmde/fundraising-phpcs requirement from ~5.0 to ~6.0 (#32)

Updates the requirements on wmde/fundraising-phpcs to permit the latest version.

---
updated-dependencies:
- dependency-name: wmde/fundraising-phpcs
  dependency-type: direct:development
...

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

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

Author: dependabot[bot]

composer.json

@@ -12,7 +12,7 @@
 	"require-dev": {
 		"phpunit/phpunit": "~9.2",
 		"symfony/cache": "^5.3",
-		"wmde/fundraising-phpcs": "~5.0",
+		"wmde/fundraising-phpcs": "~6.0",
 		"phpmd/phpmd": "~2.6",
 		"phpstan/phpstan": "^1.2",
 		"phpstan/phpstan-phpunit": "^1.0"