Update linkit to version 6

composer.json

@@ -59,7 +59,7 @@
         "drupal/gin": "^3.0@alpha",
         "drupal/gin_toolbar": "^1.0@beta",
         "drupal/honeypot": "^2.0",
-        "drupal/linkit": "^5.0",
+        "drupal/linkit": "^6.0",
         "drupal/metatag": "^1.13",
         "drupal/pathauto": "^1.8",
         "drupal/piwik_noscript": "^1.4",