Fix

Author: sebastianbergmann

src/TextUI/Command.php

@@ -843,7 +843,7 @@ private function migrateConfiguration(string $filename): void
         $result = (new SchemaDetector)->detect($filename);
 
         if (!$result->detected()) {
-            print $filename . ' does not validate against any know schema.' . PHP_EOL;
+            print $filename . ' does not validate against any known schema.' . PHP_EOL;
 
             exit(TestRunner::EXCEPTION_EXIT);
         }

tests/end-to-end/migration/unsupported-schema.phpt

@@ -14,7 +14,7 @@ PHPUnit\TextUI\Command::main();
 --EXPECTF--
 PHPUnit %s by Sebastian Bergmann and contributors.
 
-%sphpunit.xml does not validate against any know schema.
+%sphpunit.xml does not validate against any known schema.
 --CLEAN--
 <?php declare(strict_types=1);
 unlink(sys_get_temp_dir() . '/phpunit.xml');