Get rid of puppet 5 and lower artifacts

[zilchms]

Somewhere along the line of dropping puppet 5 support, some codefragments explicitely for puppet 5 and lower have remained untouched.
One example:

puppet-prometheus/manifests/config.pp

Line 222 in 3ba0d85

if versioncmp($facts['puppetversion'],'6.1.0') < 0 {

We should find all of such instances and get rid of them.

[TheMeier]

This is the only instance I could find.

[zilchms]

Could very well be the only instance, just stumbled into it and thought I should keep a record on this :P