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.

tests/shell/pipeline/commands/external.rs

@@ -148,7 +148,7 @@ mod it_evaluation {
     fn takes_rows_of_nu_value_strings() {
         Playground::setup("it_argument_test_1", |dirs, sandbox| {
             sandbox.with_files(vec![
-                EmptyFile("jonathan_likes_cake.txt"),
+                EmptyFile("jt_likes_cake.txt"),
                 EmptyFile("andres_likes_arepas.txt"),
             ]);
 
@@ -163,7 +163,7 @@ mod it_evaluation {
                 "#
             ));
 
-            assert_eq!(actual.out, "jonathan_likes_cake.txt");
+            assert_eq!(actual.out, "jt_likes_cake.txt");
         })
     }
 
@@ -436,7 +436,7 @@ mod external_command_arguments {
             "expands_table_of_primitives_to_positional_arguments",
             |dirs, sandbox| {
                 sandbox.with_files(vec![
-                    EmptyFile("jonathan_likes_cake.txt"),
+                    EmptyFile("jt_likes_cake.txt"),
                     EmptyFile("andres_likes_arepas.txt"),
                     EmptyFile("ferris_not_here.txt"),
                 ]);
@@ -450,7 +450,7 @@ mod external_command_arguments {
 
                 assert_eq!(
                     actual.out,
-                    "andres_likes_arepas.txt ferris_not_here.txt jonathan_likes_cake.txt"
+                    "andres_likes_arepas.txt ferris_not_here.txt jt_likes_cake.txt"
                 );
             },
         )
@@ -462,7 +462,7 @@ mod external_command_arguments {
             "expands_table_of_primitives_to_positional_arguments",
             |dirs, sandbox| {
                 sandbox.with_files(vec![
-                    EmptyFile("jonathan_likes_cake.txt"),
+                    EmptyFile("jt_likes_cake.txt"),
                     EmptyFile("andres_likes_arepas.txt"),
                     EmptyFile("ferris_not_here.txt"),
                 ]);

tests/shell/pipeline/commands/internal.rs

@@ -11,7 +11,7 @@ fn takes_rows_of_nu_value_strings_and_pipes_it_to_stdin_of_external() {
             r#"
                 name,rusty_luck,origin
                 Jason,1,Canada
-                Jonathan,1,New Zealand
+                JT,1,New Zealand
                 Andrés,1,Ecuador
                 AndKitKatz,1,Estados Unidos
             "#,
@@ -103,7 +103,7 @@ fn subexpression_handles_dot() {
             r#"
                 name,rusty_luck,origin
                 Jason,1,Canada
-                Jonathan,1,New Zealand
+                JT,1,New Zealand
                 Andrés,1,Ecuador
                 AndKitKatz,1,Estados Unidos
             "#,