[1.x] Improve PHP 8.4+ support by avoiding implicitly nullable types

This is a backport of #532 and corrects an oversight introduced in #482.

…code-in-tests-when-ext-sockets-is-not-enabled

Fix expected error code in tests when ext-sockets is not enabled

I don't understand why this validity check has be added.
Has per rfc 2181
(https://datatracker.ietf.org/doc/html/rfc2181#section-11), underscore
are valid character to use in an uri host.

For my specific usage, it broke for requests using docker internal
hostnames.

added test to prevent regression on URI containing underscore in host

Allow underscore character in Uri host

Builds on top of #508 by porting #543 to v1.

[1.x] Run tests on PHP 8.4 and update test environment

This changes ensures we can continue run PHPUnit on PHP 7.2 by updating PHPUnit to 8.5. This is due to recent improvements in composer as discussed in reactphp/event-loop#284.

…ment-for-PHP-7.2

[1.x] Update test environment for PHP 7.2 to compatible PHPUnit version

…nked' could lead to ReactPHP looping forever

In PHP8.1 ReflectionProperty::setAccessible was made a no-op through https://wiki.php.net/rfc/make-reflection-setaccessible-no-op in PHP8.5 it is now throwing a deprecation warning by: https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_reflectionsetaccessible

[1.x] Improve PHP 8.5+ support by avoiding deprecated `setAccessible()` calls in tests

[1.x] fix cases where a malformed HTTP request with 'Transfer-Encoding: chunked' could lead to ReactPHP looping forever

[1.x] Enforce client response max headers size