Tests: Allow mysqli tests to run in parallel

[LamentXU123]

(38.649 s) Bug #81145 (copy() and stream_copy_to_stream() fail for +4GB files) [D:\a\php-src\php-src\ext\standard\tests\file\bug81145.phpt]
(36.937 s) mysqli_fetch_array() - large packages (to test compression) [D:\a\php-src\php-src\ext\mysqli\tests\mysqli_fetch_array_large.phpt]

de-facto we could just lower the ini setting to make it loop less.

[Girgias]

Wouldn't it be better to make the openssl and mysqli test parallel, rather than faffing with tests that might need to be slow by necessity? (it might even be possible to just remove the conflict file for ext/openssl now that ephemeral ports are used)

[LamentXU123]

The second one is actually slow because the tested behavior is to break the program when memory isn't enough. We could just lower the memory amount to break it way earlier though. The first one is similar (it's testing max execution time. We don't need to wait for the default max execution time)

However, I do agree we can just remove the conflict file for ext/openssl now. Let's do it.

[LamentXU123]

(33.675 s) mysqli_fetch_array() - large packages (to test compression) [D:\a\php-src\php-src\ext\mysqli\tests\mysqli_fetch_array_large.phpt]
(30.397 s) Bug #81145 (copy() and stream_copy_to_stream() fail for +4GB files) [D:\a\php-src\php-src\ext\standard\tests\file\bug81145.phpt]

It is faster for a couple of seconds for every OpenSSL and mysql tests as observed.

[Girgias]

Probably makes sense to split the openssl test changes into its own PR.

[LamentXU123]

I split it. See #22499