Refactor handleGetUpdates to remove backwards compatibility

[devrabie]

Removes backward compatibility from handleGetUpdates in Telegram.php.

The method signature has been updated to force the $data argument to be an array, replacing the deprecated behavior where $data could optionally be an integer (representing $limit). The method handles fallback to default configurations securely and the @todo note and associated deprecation warning have been removed.

Tested with PHPUnit and checked with PHP_CodeSniffer.

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PR created automatically by Jules for task 2534040335533120128 started by @devrabie

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