fix(redundant-import): fix a warning and CI failure in nightly (#348)

src/source_impls.rs

@@ -1,12 +1,7 @@
 /*!
 Default trait implementations for [`SourceCode`].
 */
-use std::{
-    borrow::{Cow, ToOwned},
-    collections::VecDeque,
-    fmt::Debug,
-    sync::Arc,
-};
+use std::{borrow::Cow, collections::VecDeque, fmt::Debug, sync::Arc};
 
 use crate::{MietteError, MietteSpanContents, SourceCode, SourceSpan, SpanContents};
 

tests/test_repr.rs

@@ -2,7 +2,6 @@ mod drop;
 
 use self::drop::{DetectDrop, Flag};
 use miette::Report;
-use std::marker::Unpin;
 use std::mem;
 
 #[test]