Bump min version of stdlib

[waipeng]

Summary

PR #637 uses stdlib::deferrable_epp that is only available in v8.4.0[1]

[1] puppetlabs/puppetlabs-stdlib#1253

Checklist

• 🟢 Spec tests.
• 🟢 Acceptance tests.
• Manually verified. (For example puppet apply)

[bastelfreak]

I'm not sure if that's the right move. I think instead we should move stdlib >= 9.

https://github.com/puppetlabs/puppetlabs-kubernetes/blob/main/manifests/config/kubeadm.pp#L369-L370 for example still uses the deprecated merge() method: https://github.com/puppetlabs/puppetlabs-stdlib/blob/main/lib/puppet/functions/merge.rb

And that fails on puppet 8 with strict mode on. I think that metadata.json claims stdlib 9 + Puppet 8 compatibility isn't correct at the moment. The deprecated function calls should be removed and the stdlib lower version should be raised to 9.

[deric]

@bastelfreak I think bumping from 4 -> 8 is the right move right now. It would be nice to prepare at least a minor version with all those changes. Moving to stdlib >= 9 could be done in next PR, marked as a major version release.

[bastelfreak]

I think raising the stdlib version always justifies a major releases. That's how we usually did it in the past. And when you bump the lower version to 8 I think you should lower the maximum version, so basically >= 8 < 9. because it doesn't really work with Puppet 8/stdlib 9.

[deric]

The lower stdlib version change should have been done in 9f9f0eb, that is part of v8.0.0 release. It makes sense to fix that issue in v8.x branch.

However, if you would prepare 9.0.0 release with stdlib >= 8 < 9 requirement, I'm ok with that.

[waipeng]

I agree with @deric , think of this PR as fixing a bug in the lower constraint for stdlib
The issue that @bastelfreak reported will be another bug in the upper constraint for stdlib

I wonder if there's a good way to test for these kind of issues?