Support php 8.4/8.5

[BastianLedererIcinga]

Changes that had to be addressed

PHP 8.3 -> Php 8.4

Migration docs: https://www.php.net/manual/en/migration84

• Function parameters that are null by default must be declared nullable.

PHP 8.4 -> PHP 8.5

Migration Docs: https://www.php.net/manual/en/migration85

• Driver specific PDO constants are deprecated this affects some MySQL driver constants,
  instead of PDO::SQL<constant_name> use Pdo\Mysql::<constant_name>.
• ReflectionProperty::setAccessible has been deprecated, but did not have any effect since PHP 8.1.
• Passing null as $key parameter to array_key_exists() is deprecated

resolves: #1312

[sukhwinder33445]

The code looks good, @Jan-Schuppik, please approve it when the UI tests are also fine.