[new-design]: Make git optional

[BenJamesBen]

Where can we see the problem? 🤔

https://freesewing.dev/tutorials/pattern-design/part1/new-design

Suggested content

It seems that a new v3 prerequisite to running the tutorial is having the git command available. Mac and Linux come with it preinstalled, but MS Windows does not. If this is so then we should add information to the Pattern Design tutorial...

• Specifically mention that the git command is required.
• Add information about how Windows users can install it.

Additional context

For more information and discussion, please see:
https://discord.com/channels/698854858052075530/1248308667862749254/1248316733928771594
discord://discord.com/channels/698854858052075530/1248308667862749254/1248316733928771594

The git command is used in packages/new-design/lib/utils.mjs.

(We might also want to look at the existing git information in the Getting started on Windows tutorial to see if it is still valid.)
https://freesewing.dev/tutorials/getting-started-windows

[joostdecock]

I think the better option here is to make git optional. It's not strictly needed, so we should probably swallow that error.
I'll update the issue title accordingly