fix clippy (#10659)

This pr fix clippy warnings in latest clippy version(1.72.0):

Unfortunally it's not easy to handle for [try
fold](https://rust-lang.github.io/rust-clippy/master/index.html#/manual_try_fold)
warning in `start command`

Refer to known issue:
> This lint doesn’t take into account whether a function does something
on the failure case, i.e., whether short-circuiting will affect
behavior. Refactoring to try_fold is not desirable in those cases.

That's the case for our code, which does something on the failure case.

So this pr is making a little refactor on `try_commands`.

crates/nu-command/src/strings/detect_columns.rs

@@ -232,7 +232,7 @@ fn detect_columns(
                 .iter()
                 .take(end_index)
                 .skip(start_index)
-                .map(|v| v.as_string().unwrap_or(String::default()))
+                .map(|v| v.as_string().unwrap_or_default())
                 .join(" ");
             let binding = Value::string(combined, Span::unknown());
             let last_seg = vals.split_off(end_index);