[jack-worman]

Fixes two CI failures on 1.0:

• phpseclib 2.0's new X509 URL-fetch tests and SFTP rawlist tests use 2.0 internals (X509::_fetchURL(), an SFTP subclass that overrides _list()), so they fail here. update.php now skips them, and it also deletes the test files that ci.yml used to rm, so phpseclib's CI ([3.0] Test phpseclib2_compat in CI phpseclib#2265) can prepare the tests the same way.
• On PHP 7.2, Composer blocks every PHPUnit version that ^5.7|^6.0|^9.4 allows over security advisories, except 9.6.33+, which needs PHP 7.3, so the 7.2 jobs fail at composer install. This allows ^8.5 and runs the PHPUnit 9 conversion on 7.2 too, like phpseclib/phpseclib@81e21af8.