Fix post passwords getting redirected

[joshcanhelp]

Changes

Content with a password is getting redirected to the ULP.

Testing

To manually test before the fix:

1. Turn on Auth0 > Settings > Features > Universal Login Page
2. Create a new post or page
3. Set Visibility to Password Protected

4. View the post or page
5. Enter the password and submit
6. Redirected to the ULP (bad)
7. Apply the fix
8. Try steps 4 and 5 above
9. See the password-protected content

• I included manual testing steps above, if applicable
• This change adds unit test coverage
• This change has been tested in WP 5.2.2

Checklist

• All existing and new tests complete without errors
• All code quality tools/guidelines in the Contribution guide have been run/followed
• All active GitHub CI checks have passed