This includes:
- Changing "Requires PHP" in woocommerce.php
- Changing "require-php" and "config-platform-php" in composer.json
- Bumping pelago/emogrifier to ^6.0 in composer.json
- Bumping maxmind-db/reader to ^1.6 in composer.json
- Bumping composer/installers to ^1.9 in composer.json
(bump to 2.0 not possible due to conflict with Admin package)
- Removing jobs for 7.0/.1 unit test runs in CI
- Explicitly specifying the PHPUnit version to be 7.5,
otherwise it will install v8 which isn't compatible with
WordPress <5.9
The problem was that PHP 8 requires setting up a different version of
PHPUnit, and after doing that two versions were in place, one in
'vendor/phpunit' and another one in 'bin/composer/phpunit'; the
autoloader was picking the former but it should pick the later.