fix(config): add Nushell support for nvim-remote preset

[baiyeidk]

Using Nushell's native if/else syntax to avoid '&&' syntax errors in the nvim-remote editor preset.
Closes #5211

PR Description

Please check if the PR fulfills these requirements

• Cheatsheets are up-to-date (run go generate ./...)
• Code has been formatted (see here)
• Tests have been added/updated (see here for the integration test guide)
  Manual testing was performed in a Nushell environment as this is a shell-specific template change.
• Text is internationalised (see here)
• If a new UserConfig entry was added, make sure it can be hot-reloaded (see here)
• Docs have been updated if necessary
• You've read through your own file changes for silly mistakes etc

[stefanhaller]

Thanks. I can't test this because I use neither nvim-remote nor nushell, but I trust you that it works. 😄