Update facter to 4.2.8
    
    We've been using facter3 because of perf issues with facter 4. However
    this issues seems to have been fixed after 4.2.1 [1].
    
    [1] https://tickets.puppetlabs.com/si/jira.issueviews:issue-html/FACT-3045/FACT-3045.html
    
    Related-to: https://review.rdoproject.org/r/q/Ic1e8877b7ad7598b54b679143f90b16b69e074a5