Use error suppression in tests that try to test it
Use error suppression in tests that try to test it

These tests were setting error_reporting to 0 as a proxy for using
error suppression. Instead we should use '@' for real, which proves
that errors are ignored when suppression is actuall used and because
PHP 8 changes error_reporting's value when suppression is used

bugsnag/bugsnag-php,bugsnag/bugsnag-php,bugsnag/bugsnag-php