chore(signature-v4a): rename vitest.config.js to vitest.config.ts

Author: trivikr

packages/signature-v4a/vitest.config.js

@@ -0,0 +1,9 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    exclude: ["**/node_modules/**", "**/es/**"],
+    include: ["**/*.spec.ts"],
+    environment: "node",
+  },
+});