admin: prevent duplicate definition error; research why this happened

src.ts/_tests/test-wallet-hd.ts

@@ -11,13 +11,13 @@ import type { Wordlist } from "../wordlists/index.js";
 
 import type { TestCaseMnemonic, TestCaseMnemonicNode } from "./types.js";
 
-
+/*
 declare global {
     class TextDecoder {
         decode(data: Uint8Array): string;
     }
 }
-
+*/
 
 const decoder = new TextDecoder();
 function fromHex(hex: string): string {