fix some typos (#7773)

# Description

Nothing changed, just fix some typos

# 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

# 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.

Co-authored-by: Stefan Holderbach <sholderbach@users.noreply.github.com>

crates/nu-protocol/src/pipeline_data.rs

@@ -282,7 +282,7 @@ impl PipelineData {
         }
     }
 
-    /// Retrieves string from pipline data.
+    /// Retrieves string from pipeline data.
     ///
     /// As opposed to `collect_string` this raises error rather than converting non-string values.
     /// The `span` will be used if `ListStream` is encountered since it doesn't carry a span.