bump systemd: < 7.0.0

[sandwitch]

Here is a pr for changing the max version of puppet-systemd to 6.0.0

Pull Request (PR) description

This Pull Request (PR) fixes the following issues

[kenyon]

systemd is at v6.2.0, so the PR should do < 7.0.0. https://github.com/voxpupuli/puppet-systemd/blob/master/CHANGELOG.md

[kenyon]

Looks like we need @traylenator's test fixes from #685 first.

[zilchms]

@sandwitch can you rebase your PR on the current master? then i can merge this, once the CI is passing

[sandwitch]

I'm relatively new to pull request. I have updated my fork:bump_systemd. Is it good to go like this?

[zilchms]

Normally you would do something like this, after making sure every branch is up-to-date

git checkout <feature-branch>
git rebase master
git push --force

Then your branch is forwarded to the most recent change in master. But for this time I think its alright as it is :)
Thanks for your contribution :)