fix: ineffective git.depth option

[epheien]

This is a simple solution to fix this issue, which is to only use it when options such as git branch are not specified, whereas previously this option was completely unavailable.

[lewis6991]

Hmm, I'm not sure if it is worth maintaining a depth option. We already use --filter=blob:none which mostly does the same thing and is much more robust.

[epheien]

It seems that when git version >= 2.19, --filter=blob:none works better than --depth=1.

I think there are two implementation plans:

1. The git.depth option is not supported and remove it.
2. Simple implementation of git.depth but not enabled by default.

[lewis6991]

Git 2.19 came out 5 years ago. Anyone that isn't on that can live with full checkouts.

[lewis6991]

Removed git.depth here: 897ee8f