Update Drupal core to 9.2.8 and remove the core patch that was merged upstream.

See https://www.drupal.org/project/drupal/issues/3192365

composer.json

@@ -18,7 +18,7 @@
     "require": {
         "cweagans/composer-patches": "^1.6",
         "drupal/admin_toolbar": "^2.4",
-        "drupal/core": "~9.2.0",
+        "drupal/core": "~9.2.8",
         "drupal/config_update": "^1.7",
         "drupal/csv_serialization": "^2.0",
         "drupal/date_popup": "^1.1",

composer.project.json

@@ -23,11 +23,6 @@
                "web-root": "web/"
             }
         },
-        "enable-patching": true,
-        "patches": {
-            "drupal/core": {
-               "Issue #3192365: Race Condition in 'public://simpletest' mkdir Call": "https://www.drupal.org/files/issues/2021-01-12/3192365-3.patch"
-            }
-        }
+        "enable-patching": true
     }
 }