test: condense mode tests with rstest

Fix CI-failing checks.

Author: my4ng

src/uu/cp/src/copydir.rs

@@ -114,7 +114,7 @@ impl<'a> Context<'a> {
 ///
 /// For convenience while traversing a directory, the [`Entry::new`]
 /// function allows creating an entry from a [`Context`] and a
-/// [`DirEntry`].
+/// [`Path`].
 ///
 /// # Examples
 ///

src/uu/cp/src/cp.rs

@@ -1789,6 +1789,7 @@ pub(crate) fn copy_attributes(
     let source_metadata = fs::symlink_metadata(source)
         .map_err(|e| CpError::IoErrContext(e, context_for(source, dest)))?;
 
+    #[cfg(unix)]
     let mut failed_to_set_ownership = false;
 
     // Ownership must be changed first to avoid interfering with mode change.