test(api): remove committed describe.only from webauthn tests

A describe.only in test/api/webauthn-test.js silently reduced the grunt
api mochaTest target to the 8 WebAuthn tests, skipping every other API
suite loaded in the same mocha process. With the .only removed the full
API test set (291 tests) runs again.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LWnLbVpaso4kpiK7wXLm6d

Author: andris9

test/api/webauthn-test.js

@@ -130,7 +130,7 @@ function base64UrlDecode(value) {
     return Buffer.from(input, 'base64');
 }
 
-describe.only('API WebAuthn', function () {
+describe('API WebAuthn', function () {
     this.timeout(10000); // eslint-disable-line no-invalid-this
 
     const password = 'webauthnsecretvalue';