Running `upsun create` does not ignore .upsun/local/ on Windows

[ehmatthes]

Hi, I'm working on a plugin for django-simple-deploy that automates deployment of Django projects to Upsun. This is an update of the dsd-platformsh plugin that worked for the past several years for Platform.sh.

When I run upsun create on macOS, the .upsun/local/ directory that's created is excluded by version control due to this entry in .git/info/exclude:

# Automatically added by the Upsun CLI
/.upsun/local
/_www

That works; running git status after calling upsun create shows a clean Git status.

On Windows, the .upsun\local directory is not excluded by version control. This is what gets added to .git\info\exclude on Windows:

# Automatically added by the Upsun CLI
/.upsun\local
/_www

Running git status does not return a clean status:

>git status
On branch main
Untracked files:
  (use "git add <file>..." to include in what will be committed)
        .upsun/

If I replace /.upsun\local with /.upsun/local in .git/info/exclude, the .upsun/local directory is excluded.

I assume this is a mistake when writing the entry to .git/info/exclude on Windows. Is that correct, and if so can this be fixed?

Thank you.