testing/php81: security upgrade to 8.1.31
- CVE-2024-8929
- CVE-2024-8932
- CVE-2024-11233
- CVE-2024-11234
- CVE-2024-11236
ref https://github.com/php/php-src/commit/a001ad33f07d9dcfb604436db3bf532e4b52e7d3
ref https://github.com/php/php-src/commit/a001ad33f07d9dcfb604436db3bf532e4b52e7d3