[php-src] Issue #21176: php 8.1.34 - Unit test failure

Issue: https://github.com/php/php-src/issues/21176
Author: tharukaDacquia

### Description

The following code:
[https://github.com/php/php-src/blob/PHP-8.5.3/ext/pdo_pgsql/tests/ghsa-8xr5-qppj-gvwj.phpt](https://github.com/php/php-src/blob/PHP-8.5.3/ext/pdo_pgsql/tests/ghsa-8xr5-qppj-gvwj.phpt)
```php
--TEST--
#GHSA-8xr5-qppj-gvwj: NULL Pointer Derefernce for failed user input quoting
--EXTENSIONS--
pdo
pdo_pgsql
--SKIPIF--
<?php
require_once dirname(__FILE__) . '/../../../ext/pdo/tests/pdo_test.inc';
require_once dirname(__FILE__) . '/config.inc';
PDOTest::skip();
?>
--FILE--
<?php
require_once dirname(__FILE__) . '/../../../ext/pdo/tests/pdo_test.inc';
require_once dirname(__FILE__) . '/config.inc';
$db = PDOTest::test_factory(dirname(__FILE__) . '/common.phpt');
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);

$sql = "SELECT * FROM users where username = :username";
$stmt = $db->prepare($sql);

$p1 = "alice\x99";
var_dump($stmt->execute(['username' => $p1]));

?>
--EXPECT--
bool(false)
```

Resulted in this output:
```
========DIFF========
001+ Fatal error: Uncaught PDOException: SQLSTATE[22021]: Character not in repertoire: 7 ERROR:  invalid byte sequence for encoding "UTF8": 0x99 in /home/webuser/ext/pdo_pgsql/tests/ghsa-8xr5-qppj-gvwj.php:12
001- bool(false)
002+ Stack trace:
003+ #0 /home/webuser/ext/pdo_pgsql/tests/ghsa-8xr5-qppj-gvwj.php(12): PDOStatement->execute(Array)
004+ #1 {main}
005+   thrown in /home/webuser/ext/pdo_pgsql/tests/ghsa-8xr5-qppj-gvwj.php on line 12
========DONE========
FAIL #GHSA-8xr5-qppj-gvwj: NULL Pointer Derefernce for failed user input quoting [ext/pdo_pgsql/tests/ghsa-8xr5-qppj-gvwj.phpt]
```

But I expected this output instead:
```
Based on the unit test code as i think we can't expect `false` as expectation since we enabling `$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION)`
```


### PHP Version

```plain
php 8.1.34
```

### Operating System

Ubuntu 18.04