Make `enable-new-git-file-globbing=true` the default and only option

# Summary

Make `enable-new-git-file-globbing=true` the only behavior. It's more consistent with our other globbing uses. https://github.com/argoproj/argo-cd/pull/13314

# Motivation

It's more intuitive. Using just the new globbing format will also eliminate one use of the `git` CLI, moving us further towards being able to go distroless.

# Proposal

Delete the code that did it the old way, leave the code that does it the new way.

Start by locating the old and new Git file-globbing implementations, then review the behavior described in pull request #13314. Run the relevant tests and verify that only the new globbing behavior remains and the old Git CLI path is removed.

Written by the indexing model from the issue text.