refactor: remove unnecessary Workspace::preload

Already did that in
https://github.com/rust-lang/cargo/blob/2f17770a15b5e6abe3348d4fcefc08b223e05968/src/cargo/ops/resolve.rs#L375-L378

See also cda5f82

Author: weihanglo

src/cargo/ops/resolve.rs

@@ -416,7 +416,6 @@ pub fn resolve_with_previous<'gctx>(
         None => root_replace.to_vec(),
     };
 
-    ws.preload(registry);
     let mut resolved = resolver::resolve(
         &summaries,
         &replace,