Added new PersistAuth endpoint to spec

[telday]

Desired Outcome

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the original request that resulted in these code changes? Feel free to copy
this information from the connected issue.

Implemented Changes

Added the new persist authenticator endpoint to the spec file under a new configuration tag.

Connected Issue/Story

CyberArk internal issue link: Relevant Conjur PR

Changelog

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Test coverage

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Documentation

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Behavior

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Security

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