Fix warnings and old names (#8457)

# Description

This fixes up some clippy warnings and removes some old names/info from
our unit tests

# User-Facing Changes

Internal changes only

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-command/tests/commands/enter.rs

@@ -10,7 +10,7 @@ fn knows_the_filesystems_entered() {
             .within("red_pill")
             .with_files(vec![
                 EmptyFile("andres.nu"),
-                EmptyFile("jonathan.nu"),
+                EmptyFile("jtnu"),
                 EmptyFile("yehuda.nu"),
             ])
             .within("blue_pill")
@@ -32,7 +32,7 @@ fn knows_the_filesystems_entered() {
                 enter expected
                 mkdir recycled
                 enter ../red_pill
-                mv jonathan.nu ../expected
+                mv jtnu ../expected
                 enter ../blue_pill
                 cp *.nxt ../expected/recycled
                 p
@@ -54,7 +54,7 @@ fn knows_the_filesystems_entered() {
         assert!(files_exist_at(
             vec![
                 Path::new("andres.nu"),
-                Path::new("jonathan.nu"),
+                Path::new("jtnu"),
                 Path::new("yehuda.nu"),
             ],
             expected