psr7-string-stream/.builds d---------
Sync with Packagist
Check-in CI improvements

This commit pulls in ancarda/coverage-enforcer which ensures code
coverage remains at 100%. Additionally, PHPUnit was raised to 9.x and
now has a nicer configuration style.

This brings psr7-string-stream inline with how I do PHP development
these days.
Disable coverage checking on PHP 8.0

To be fixed at a later date
Implement SourceHut CI