[php-src] PR #24379: Fix GH-24372: Keep stmt->executed set across PDOStatement::execute()

Pull Request: https://github.com/php/php-src/pull/24379 Author: iliaal 11690db1787 clears stmt->executed on re-execute. pdo_oci reads that as a first execution and reallocates its column buffers while PDO core keeps the old descriptions, so the second fetch crashes; pdo_ibm leaks instead. A failed execute() is now tracked in a separate bit and executed is left alone. closeCursor() followed by execute() crashes pdo_oci the same way on every version; that needs a pdo_oci fix (https://github.com/php/pecl-database-pdo_oci/pull/46). This is a much more simplified approach, personally I think this is much cleaner than the original Fixes #24372