refactor(tvix/eval): remove Box in new_suspended_native

This is unnecessary, Rc already provides all the boxing we need.

Change-Id: I08cf0939c48da43f04c847526c7e5dae5336d528
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7749
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>

tvix/eval/src/value/thunk.rs

@@ -86,9 +86,7 @@ impl Thunk {
         })))
     }
 
-    pub fn new_suspended_native(
-        native: Rc<Box<dyn Fn(&mut VM) -> Result<Value, ErrorKind>>>,
-    ) -> Self {
+    pub fn new_suspended_native(native: Rc<dyn Fn(&mut VM) -> Result<Value, ErrorKind>>) -> Self {
         let span = codemap::CodeMap::new()
             .add_file("<internal>".to_owned(), "<internal>".to_owned())
             .span;