GitHub strategy should respect composer.json PHP requirements

[mpociot]

I'm currently running into a little problem with Expose in combination with the phar updater where I'm unsure how to fix this.

The problem is that I need to tag a new version (2.6.0) which will drop PHP 8.0 support
The GitHub strategy updater only checks for a newer version though - regardless of the PHP version constraints.
This means that running expose self-update on version 2.5.0 with PHP 8.0 will see that there's a new version and download it – even though this new version will not work.

As I said, I'm not really sure what's the best way to fix this.

Checking for PHP version constraints in the updater could work, but we would miss intermediate updates. Imagine a user is on version 2.4 and wants to update.
The updater only detects the latest version, which would be 2.6 and not run on PHP 8.0, while a 2.5 release might be available.