[php-src] PR #24049: phar: check php_stream_filter_create() result for bzip2.compress in phar_tar_flush() and phar_flush_ex()

Pull Request: https://github.com/php/php-src/pull/24049 Author: ushevchenko **Fixes GH-24048** The bzip2 branches of phar_tar_flush() (ext/phar/tar.c) and phar_flush_ex() (ext/phar/phar.c) pass the result of php_stream_filter_create("bzip2.compress", ...) to php_stream_filter_append() without checking it for NULL. The gzip branches of the same functions already handle this case. This adds the same check to both bzip2 branches: on failure an error message is set and EOF is returned. In phar_tar_flush() the contents are copied uncompressed first and newfile is closed, exactly as in the gzip branch. With the default parameters phar passes, php_stream_filter_create() cannot realistically return NULL here, so there is no test; this is a robustness and consistency fix. Found by Linux Verification Center (https://portal.linuxtesting.ru) using SVACE.