fix: nushell language syntax update

[lorenzk]

Summary

Nushell integration is broken because of the deprecated let-env, see https://www.nushell.sh/commands/docs/let-env.html#frontmatter-title-for-removed for details.

Fixes: #1609

Other Information

There is already pull request #1610 that does not seem to be worked on at the moment.

Manual testing on my MacBook M1 worked. I tried running the automated test suite, but there were too many unrelated errors. I hope your CI will tell us whether I did everything right.

Linting worked.

[lorenzk]

I made a mistake that I only noticed after restarting my iTerm2. Fixed it in the third commit, but did not rebase or anything to keep things in historical order. Feel free to merge/squash however you like.

[hyperupcall]

Thanks! When I test the changes, I recieve two errors: One I commented about and another about the ^asdf syntax. I'm not able to run CI here, but you can see the output from one of my forks. The only difference is that I squashed your changes.

About the ^asdf syntax, it seems that it is supposed to refer to the current module, but it does not seem to work anymore. I get the error:

# × External command failed
#      ╭─[/Users/runner/work/asdf/asdf/asdf.nu:98:1]
#   98 │
#   99 │         ^asdf plugin list $flags | lines | parse -r $template | str trim
#      ·          ──┬─
#      ·            ╰── command 'asdf' was not found but it exists in module 'asdf'; try importing it with `use`
#  100 │     }
#      ╰────

[jthegedus]

Before we can merge this can you @lorenzk address the comment from @hyperupcall ?

[jthegedus]

Thanks

[lorenzk]

Sorry for not replying earlier. You're awesome, thanks! Assuming brew to exist made no sense at all on my part.

[jthegedus]

Sorry for not replying earlier. You're awesome, thanks! Assuming brew to exist made no sense at all on my part.

All good mate, you did the heavy lifting, much appreciated 🙇