minor symfony#59717 Fix return type of mock factory in Redis ConnectionTest (alexandre-daubois)

This PR was merged into the 7.3 branch.

Discussion
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Fix return type of mock factory in Redis `ConnectionTest`

| Q             | A
| ------------- | ---
| Branch?       | 7.3
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Issues        | -
| License       | MIT

The return type is wrong, causing warnings being raised by IDE when calling mock methods on the return value.

Commits
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eb3bf17 Fix return type of mock in Redis `ConnectionTest`

Author: fabpot

src/Symfony/Component/Messenger/Bridge/Redis/Tests/Transport/ConnectionTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Messenger\Bridge\Redis\Tests\Transport;
 
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Messenger\Bridge\Redis\Transport\Connection;
 use Symfony\Component\Messenger\Exception\TransportException;
@@ -524,7 +525,7 @@ public function testKeepaliveWithTooSmallTtl()
         $connection->keepalive('redisid-123', 3000);
     }
 
-    private function createRedisMock(): \Redis
+    private function createRedisMock(): MockObject&\Redis
     {
         $redis = $this->createMock(\Redis::class);
         $redis->expects($this->any())