oci: use a newer stdlib Vec API

This wasn't yet stabilized when the code was first written but newer
patches have already added the use of this function in other parts of
the same file, so this ought to be safe by now.

Author: allisonkarlitskaya

crates/composefs-oci/src/tar.rs

@@ -173,11 +173,7 @@ fn path_from_tar(pax: Option<Box<[u8]>>, gnu: Vec<u8>, short: &[u8]) -> PathBuf
     }
 
     // Drop trailing '/' characters in case of directories.
-    // https://github.com/rust-lang/rust/issues/122741
-    // path.pop_if(|x| x == &b'/');
-    if path.last() == Some(&b'/') {
-        path.pop(); // this is Vec<u8>, so that's a single char.
-    }
+    path.pop_if(|x| x == &b'/');
 
     PathBuf::from(OsString::from_vec(path))
 }