feat(`forge`): avoid repulling in dependencies when using git worktree

### Component

Forge

### Describe the feature you would like

I often find myself in the following situation.
I work on a new feature for repo `r` so I:

```sh
$ cd r
$ git worktree add -b new-feature-a features/new-feature-a
$ cd features/new-feature-a
$ git submodule sync
$ foundry i
```

This process is annoying because I have to sync submodules and install dependencies which is often long, instead I would expect dependencies to be shared across worktrees, or at least cached.

### Additional context

_No response_

Start with the Forge workflow invoked by `foundry i` after `git worktree add`, then examine how `git submodule sync` and dependency installation behave in a worktree. Done means dependencies are shared across worktrees or cached so the documented sequence does not repull or reinstall them unnecessarily.

Written by the indexing model from the issue text.