Avoid enforcing distribution ID uniqueness for extras (#4104)

## Summary

The condition enforced here isn't quite right. The same dependency can
appear multiple times, as long as the extra is different.

Closes https://github.com/astral-sh/uv/issues/4101.

crates/uv-resolver/src/lock.rs

@@ -340,7 +340,7 @@ impl TryFrom<LockWire> for Lock {
             dist.dependencies.sort();
             for windows in dist.dependencies.windows(2) {
                 let (dep1, dep2) = (&windows[0], &windows[1]);
-                if dep1.id == dep2.id {
+                if dep1 == dep2 {
                     return Err(LockError::duplicate_dependency(
                         dist.id.clone(),
                         dep1.id.clone(),