test_runner: correct "already mocked" error punctuation placement

PR-URL: #58840
Reviewed-By: Pietro Marchini <[email protected]>
Reviewed-By: Ethan Arrowood <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>

Author: JakobJingleheimer

lib/internal/test_runner/mock/mock.js

@@ -526,7 +526,7 @@ class MockTracker {
 
     if (baseURL.searchParams.has(kMockSearchParam)) {
       throw new ERR_INVALID_STATE(
-        `Cannot mock '${specifier}.' The module is already mocked.`,
+        `Cannot mock '${specifier}'. The module is already mocked.`,
       );
     }