Updates config for fish vi mode.
Updates config for fish vi mode.

Updates fish config to redirect `stderr` to `/dev/null`. This fixes [an
issue](https://github.com/syl20bnr/spacemacs/issues/12221) in spacemacs where
switching projectile projects was failing with an error like:

```
file-error "Setting current directory" "File name too long"
```

tmr08c/dotfiles,tmr08c/dotfiles