fix(copy): improve copy function so that it creates a new dictionary …

…with no prototype

index.ts

@@ -2,7 +2,7 @@ import {Dictionary, Key, ReadonlyDictionary} from "dictionary-types";
 
 /** Creates a shallow copy of the specified dictionary. */
 export function copy<T, K extends Key, L extends K = K>(dictionary: ReadonlyDictionary<T, K>): Dictionary<T, L> {
-    return {...dictionary};
+    return Object.assign(Object.create(null), dictionary);
 }
 
 // @ts-ignore duplicate identifier: These overrides constitute the exported declaration, the implementation is below.