Inconsistent handling of invalid headers causes unexpected behavior

Description

The following code:

<?php
header( "X-Foo;: hello" );
header( "X-Foo\t: hello" );
header( "X-Foo\n: hello" );

The 3rd one results in a warning (Header may not contain more than a single header, new line detected) and the header is not set.
The other 2 however are sent without a warning. The 2nd one will get fixed by nginx, however the 1st one passes through (see https://github.com/nginx/nginx/issues/899)

This not only is inconsistent, this also allows for certain attack vectors if the request is proxied and the proxy does not handle the invalid headers correctly (sorry, can't go into detail on this at this moment in time, due to pending security reports)

Since headers are apparently getting validated in PHP already (otherwise we wouldn't have an error for the 3rd one), this validation should be fixed to strictly check if the provided header adheres to the HTTP header standards

PHP Version

PHP 8.4, however affects previous PHP versions similarly

Operating System

No response

Start by reproducing the three header() calls described in the issue and inspect PHP's header validation path for how semicolons, tabs, and newlines are handled. The work is done when invalid header syntax is consistently rejected with an appropriate warning and valid headers remain unaffected; add coverage for the three examples.