[fix] Supertest - GCP Error - 2 UNKNOWN: Getting metadata from plugin failed with error: Unexpected Gaxios Error

## Describe the bug

**Node.js version:** v25.1.0

**OS version:** macOS Tahoe 26.1

**Description:** Getting an error "2 UNKNOWN: Getting metadata from plugin failed with error: Unexpected Gaxios Error" while trying to retrieve the GCP secret.

## Actual behavior

Getting an error "2 UNKNOWN: Getting metadata from plugin failed with error: Unexpected Gaxios Error" while trying to retrieve the GCP secret.

## Expected behavior

Should be able to retrieve the GCP secrets successfully without any errors.

## Code to reproduce

import request, { Response } from "supertest";

describe("Endpoints", () => {
let authToken: string;
beforeAll(async () => {
authToken = await getAccessToken(BASE_URL);
});

export async function getAccessToken(baseUrl: string): Promise {
const username = await getSecretValue("");
const reqBody = "";

request(baseUrl)
.post("/auth/token")
.auth(username)
.set("Content-Type", "application/x-www-form-urlencoded")
.send(reqBody);
}

import { SecretManagerServiceClient } from '@google-cloud/secret-manager';
import { gcp_secret_project_name } from '../../config';

const client = new SecretManagerServiceClient();

export async function getSecretValue(secretId: string): Promise {
const [version] = await client.accessSecretVersion({
name: `projects/${gcp_secret_project_name}/secrets/${secretId}/versions/latest`,
});

return version.payload?.data?.toString() || '';
}

Failing in this line of code: await client.accessSecretVersion({
name: `projects/${gcp_secret_project_name}/secrets/${secretId}/versions/latest`,
});
with:
`2 UNKNOWN: Getting metadata from plugin failed with error: Unexpected Gaxios Error
`

## Checklist

- [X] I have searched through GitHub issues for similar issues.
- [X] I have completely read through the README and documentation.
- [X] I have tested my code with the latest version of Node.js and this package and confirmed it is still not working.