Fix PHP Monolog LogsHandler constructor in logs docs (#19640)

## DESCRIBE YOUR PR

Fixes #19177

The PHP logs setup snippet still constructed LogsHandler with a Hub
argument. In sentry/sentry 4.x that constructor only takes a log level
(and bubble), so the sample failed as written. Updated it to match the
working 4.x call.

## IS YOUR CHANGE URGENT?

- [ ] Urgent deadline (GA date, etc.): YYYY-MM-DD
- [ ] Other deadline: YYYY-MM-DD
- [x] No deadline: Not urgent, can wait up to 1 week+

## PRE-MERGE CHECKLIST

- [ ] Checked Vercel preview for correctness, including links
- [ ] PR was reviewed and approved by any necessary SMEs (subject matter
experts)
- [ ] PR was reviewed and approved by a member of the [Sentry docs
team](https://github.com/orgs/getsentry/teams/docs)

## LEGAL BOILERPLATE

Look, I get it. The entity doing business as "Sentry" was incorporated
in the State of Delaware in 2015 as Functional Software, Inc. and is
gonna need some rights from me in order to utilize my contributions in
this here PR. So here's the deal: I retain all rights, title and
interest in and to my contributions, and by keeping this boilerplate
intact I confirm that Sentry can use, modify, copy, and redistribute my
contributions, under Sentry's choice of terms.

## Test plan
- [x] Compared against sentry-php 4.30 LogsHandler::__construct
- [ ] Spot check https://docs.sentry.io/platforms/php/logs/ after merge

---------

Co-authored-by: Martin Linzmayer <martin.linzmayer@sentry.io>
Co-authored-by: Giannis Gkiortzis <58184179+giortzisg@users.noreply.github.com>

Author: 3 people

platform-includes/logs/setup/php.mdx

@@ -22,10 +22,7 @@ use Monolog\Logger;
 ]);
 
 $log = new Logger('app');
-$log->pushHandler(new \Sentry\Monolog\LogsHandler(
-    hub: \Sentry\SentrySdk::getCurrentHub(),
-    level: Level::Info,
-));
+$log->pushHandler(new \Sentry\Monolog\LogsHandler(Level::Info, true, false));
 
 // Your existing Monolog usage will now send logs to Sentry
 $log->info('Application started');