puppetlabs/stdlib 9 breaks compatibility with Puppet 6

[danielparks]

My most recent release switched to the stdlib::shell_escape() syntax, which appears to be required by puppetlabs/stdlib (changelog).

I semi-incorrectly reported with as fixing Puppet 8 support, but did not update the metadata to not support Puppet 6. It turns out that Puppet 8 makes deprecations an error by default. See puppetlabs/puppetlabs-stdlib#1365.

One of two things needs to happen:

• Downgrade to puppetlabs/stdlib < 9 and revert to the shell_escape() syntax. This would maintain support with Puppet 6 through 8.
• Update metadata to only support Puppet ≥ 7 and puppetlabs/stdlib ≥ 9. This might cause problems for anybody who needs to use an old version of puppetlabs/stdlib, which is particularly likely because of this issue.

I suppose I could try checking for the existence of stdlib::shell_escape and calling the correct function depending on that.