Remove unused code

Author: mu001999

src/tools/rust-analyzer/crates/salsa/salsa-macros/src/database_storage.rs

@@ -241,11 +241,3 @@ impl Parse for QueryGroup {
         Ok(QueryGroup { group_path })
     }
 }
-
-struct Nothing;
-
-impl Parse for Nothing {
-    fn parse(_input: ParseStream<'_>) -> syn::Result<Self> {
-        Ok(Nothing)
-    }
-}