remove obsolete comment

crates/red_knot/src/db.rs

@@ -155,14 +155,14 @@ pub(crate) mod tests {
             file_to_module(self, file_id)
         }
 
-        fn infer_symbol_type(&self, file_id: FileId, symbol_id: SymbolId) -> Type {
-            infer_symbol_type(self, file_id, symbol_id)
-        }
-
         fn path_to_module(&self, path: &Path) -> Option<Module> {
             path_to_module(self, path)
         }
 
+        fn infer_symbol_type(&self, file_id: FileId, symbol_id: SymbolId) -> Type {
+            infer_symbol_type(self, file_id, symbol_id)
+        }
+
         fn symbol_table(&self, file_id: FileId) -> Arc<SymbolTable> {
             symbol_table(self, file_id)
         }

crates/red_knot/src/types/infer.rs

@@ -6,8 +6,6 @@ use crate::types::Type;
 use crate::FileId;
 use ruff_python_ast::AstNode;
 
-// TODO this should not take a &mut db, it should be a query, not a mutation. This means we'll need
-// to use interior mutability in TypeStore instead, and avoid races in populating the cache.
 #[tracing::instrument(level = "trace", skip(db))]
 pub fn infer_symbol_type<Db>(db: &Db, file_id: FileId, symbol_id: SymbolId) -> Type
 where