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/format_conversions/csv.rs

@@ -82,7 +82,7 @@ fn infers_types() {
             r#"
                 first_name,last_name,rusty_luck,d
                 Andrés,Robalino,1,d
-                Jonathan,Turner,1,d
+                JT,Turner,1,d
                 Yehuda,Katz,1,d
                 Jason,Gedge,1,d
             "#,
@@ -109,7 +109,7 @@ fn from_csv_text_to_table() {
             r#"
                 first_name,last_name,rusty_luck
                 Andrés,Robalino,1
-                Jonathan,Turner,1
+                JT,Turner,1
                 Yehuda,Katz,1
             "#,
         )]);
@@ -136,7 +136,7 @@ fn from_csv_text_with_separator_to_table() {
             r#"
                 first_name;last_name;rusty_luck
                 Andrés;Robalino;1
-                Jonathan;Turner;1
+                JT;Turner;1
                 Yehuda;Katz;1
             "#,
         )]);
@@ -163,7 +163,7 @@ fn from_csv_text_with_tab_separator_to_table() {
             r#"
                 first_name	last_name	rusty_luck
                 Andrés	Robalino	1
-                Jonathan	Turner	1
+                JT	Turner	1
                 Yehuda	Katz	1
             "#,
         )]);
@@ -189,7 +189,7 @@ fn from_csv_text_skipping_headers_to_table() {
             "los_tres_amigos.txt",
             r#"
                 Andrés,Robalino,1
-                Jonathan,Turner,1
+                JT,Turner,1
                 Yehuda,Katz,1
             "#,
         )]);