- fix(email): transactional emails are all not sent if `Use system wide (transactional) email settings` is disabled and no other email provide is setup on the Notifications page
- fix(email): no emails are sent if SMTP username and SMTP password are empty (which is the case in dev for example)
- fix(email): Wrong test email notification is used, causing the transactional email test notification to fail if no email provider is set up on the Notifications page.
Related to #4311
Add option to configure SMTP settings without encryption.
* Update `app/Livewire/Notifications/Email.php` and `app/Livewire/SettingsEmail.php` to include "No Encryption" option in the `smtpEncryption` field and update validation rules.
* Modify `app/Notifications/Channels/EmailChannel.php` to handle the "No Encryption" option in the `bootConfigs` method.
* Add `set_transanctional_email_settings` function in `app/Livewire/Help.php` to support the "No Encryption" option.
* Update `config/mail.php` to handle the "No Encryption" option in the mail configuration.
