Change 'blacklist' verbiage to 'denylist' in `cpe_chefctl`

[ChefAustin]

We should change the use of blacklist to denylist in cpe_chefctl.

See: https://github.com/uber/cpe-chef-cookbooks/blob/876737a2ca5afd06516899d687091476bdc0fd0d/cpe_chefctl/files/default/chefctl.rb#L449

[ChefAustin]

Upstream issue (facebook/chef-utils#80) and PR (facebook/chef-utils#81) created and pending review/merge.

[mikermcneil]

More context for any other folks landing from search engines who might be new to the topic: https://about.gitlab.com/handbook/communication/top-misused-terms/#list-of-top-misused-terms

[mikermcneil]

(upstream PR got merged btw)