Add swoole extension

[johnsudaar]

This was required by a user on the support.

Swoole is an asynchronous library used by some PHP applications: https://www.php.net/manual/en/book.swoole.php

Contact https://app.intercom.com/a/apps/w4oogu7s/inbox/inbox/all/conversations/12375700012849 when done

[Soulou]

For context: not an official extension, Heroku doesn't have it either: heroku/heroku-buildpack-php#297

[johnsudaar]

This extension is needed by this project: https://shlink.io/

[tillkruss]

@Soulou: Feel free to submit a PR here: https://github.com/cachewerk/heroku-php-extensions

[johnsudaar]

It's also needed by Laravel Octane

Contact https://app.intercom.com/a/apps/w4oogu7s/inbox/inbox/all/conversations/12375700058627 when done

[Frzk]

According to my tests, it works by just specifying:

{
    "require": {
        "ext-swoole": "*"
    }
}

in composer.json. Successfully tested with scalingo-22 and PHP 8.1.23 and 8.2.10.

I guess this is the consequence of #286

I think we can close this now. Please re-open an issue if need be.