minor #6218 Use composer/xdebug-handler v3 (gharlan)

This PR was squashed before being merged into the master branch (closes #6218).

Discussion
----------

Use composer/xdebug-handler v3

closes #6213

Commits
-------

8e2912138 Use composer/xdebug-handler v3

composer.json

@@ -18,7 +18,7 @@
         "ext-json": "*",
         "ext-tokenizer": "*",
         "composer/semver": "^3.2",
-        "composer/xdebug-handler": "^2.0",
+        "composer/xdebug-handler": "^3.0",
         "doctrine/annotations": "^1.13",
         "php-cs-fixer/diff": "^2.0",
         "symfony/console": "^4.4.20 || ^5.1.3 || ^6.0",