[5.x]: E-Mail validation rejects a valid e-mail address with ß

[MoritzLost]

What happened?

Description

I've got a client that has the German special character ß in their e-mail address. While unusual, it is a valid address. However, I can't create a user account because Craft rejects it:

Error: Email is not a valid email address.

Steps to reproduce

1. Create a new user with the email address specialß[email protected] and hit save.

Expected behavior

Any valid email should pass validation, including emails with ß in it.

Actual behavior

The email is incorrectly identified as invalid and I can't save the user account.

Craft CMS version

5.6.11

PHP version

8.3

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

No response