Steps to reproduce:
1. Set up an AbortController
2. <input autocomplete="username webauthn"> and a button whose click handler will call the abortController.abort(), hide the username, and show a password control.
3. Perform webauthn get with conditional mediation:
navigator.credentials.get({
  signal: abortController.signal,
  mediation: 'conditional',
  publicKey: {
    challenge: <challengeFromServer>,
  },
  allowCredentials: []
});
3. Click the input, conditional UI appears.
4. Click the abort control.
6. Set focus to the password field.
7. Conditional UI appears again. (If user attempts to use the passkey, console shows error "AbortError: Aborted by AbortSignal".)

Expected behavior:
In step 7, no conditional UI should be displayed, since the get has been aborted.