[BUG]: Replace deprecated flag in Nushell

[colececil]

Version
0.6.10

OS
Windows

Describe the bug

The vfox setup script for Nushell utilizes get -i, and the -i flag has now been deprecated in favor -o. This causes the following warning to appear whenever opening a new shell in Nushell:

Warning: nu::parser::deprecated

  ⚠ Flag deprecated.
    ╭─[<nushellConfigDirectory>\vfox.nu:20:43]
 19 │   $env.config = ($env.config | upsert hooks.pre_prompt {
 20 │     let currentValue = ($env.config | get -i hooks.pre_prompt)
    ·                                           ─┬
    ·                                            ╰── get --ignore-errors was deprecated in 0.106.0 and will be removed in a future release.
 21 │     if $currentValue == null {
    ╰────
  help: This flag has been renamed to `--optional (-o)` to better reflect its behavior.

The -i in the Nushell script should be replaced with -o to remove this warning and ensure vfox keeps working in future versions of Nushell.