[red-knot] Resolve symbols from builtins.pyi in the stdlib if they cannot be found in other scopes (#12390)

Co-authored-by: Carl Meyer <carl@astral.sh>

crates/red_knot_python_semantic/src/lib.rs

@@ -6,6 +6,7 @@ pub use db::{Db, Jar};
 pub use semantic_model::{HasTy, SemanticModel};
 
 pub mod ast_node_ref;
+mod builtins;
 mod db;
 mod node_key;
 pub mod semantic_index;