Remove obsolete chefspec reload guards

What does this MR do?

We now mock Kernel.load during tests - https://gitlab.com/gitlab-org/omnibus-gitlab/blob/3c3605a742b672ff2a799104440599cbb669023e/spec/chef_helper.rb#L61-65

Related issues

Closes #3326 (closed)

Checklist

See Definition of done.

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Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
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Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
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• Tests added
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