Executable static build of PIE+PHP

[asgrim]

It may be possible to distribute PIE as a complete standalone binary, using Static PHP - i.e. PHP itself, the extensions that PIE depends on, and PIE itself.

The huge benefit for this is it eliminates the need for specific PHP versions on the system; currently PIE requires PHP 8.1, but that means to install an extension on an older PHP version, you must have two PHP versions (one to run PIE, plus your target) and use the --with-php-config=... option. If we build it all together, it is standalone and much more portable.

This has an added side benefit in the future of being able to run without ANY dependencies, and means we could "drop" older PHP versions for the PIE tool itself, eventually (assuming we drop the PHAR distribution).

[rvanlaak]

That'd be fun, especially as Static PHP seems to leverage PIE itself as well 🎉 https://github.com/crazywhalecc/static-php-cli/blob/9fdfef50574d6eed60d707e0f0d2a304c7c7825d/docs/en/develop/source-module.md?plain=1#L39