Support build constraints (#5639)

## Summary

Partially resolves #5561. Haven't added overrides support yet but I can
add it tomorrow if the current approach for constraints is ok.

## Test Plan

`cargo test`

Manually checked trace logs after changing the constraints.

crates/uv-dev/src/build.rs

@@ -74,10 +74,12 @@ pub(crate) async fn build(args: BuildArgs) -> Result<PathBuf> {
         &cache,
     )?;
     let build_options = BuildOptions::default();
+    let build_constraints = [];
 
     let build_dispatch = BuildDispatch::new(
         &client,
         &cache,
+        &build_constraints,
         python.interpreter(),
         &index_urls,
         &flat_index,