BUG: add git safe directory for centrally deployed git repos

[ZLLentz]

Description

• If it has not already been done, add the ansible root directory as a safe directory for the purposes of git when we need to use git to check the version number.

Motivation and Context

• After running a plc setup, we are supposed to document the results.
• Providing some version information to the user at exit is really helpful for making it possible to complete this step.
• "git describe" is the simplest way to get this information
• All git commands refuse to run for shared directories unless safe.directory has an entry for the cloned git repo path.

How Has This Been Tested?

• Interactively only, as me

Where Has This Been Documented?

• Only here and in jira

Pre-merge checklist

• Code works interactively
• Code works interactively in dry_run mode
• Code contains descriptive docstrings, including context and API
• Pre-commit passes on GitHub Actions
• Documentation under https://confluence.slac.stanford.edu/display/PCDS/TcBSD has been updated appropriately

[tangkong]

LGTM