Fix some #[cfg_attr(not(doc), repr(..))]

Now that #90435 seems to have been resolved.

library/std/src/path.rs

@@ -2079,10 +2079,8 @@ impl AsRef<OsStr> for PathBuf {
 #[stable(feature = "rust1", since = "1.0.0")]
 // `Path::new` current implementation relies
 // on `Path` being layout-compatible with `OsStr`.
-// However, `Path` layout is considered an implementation detail and must not be relied upon. We
-// want `repr(transparent)` but we don't want it to show up in rustdoc, so we hide it under
-// `cfg(doc)`. This is an ad-hoc implementation of attribute privacy.
-#[cfg_attr(not(doc), repr(transparent))]
+// However, `Path` layout is considered an implementation detail and must not be relied upon.
+#[repr(transparent)]
 pub struct Path {
     inner: OsStr,
 }