test: fix soucre to source

PR-URL: https://github.com/nodejs/node/pull/55038
Reviewed-By: Jake Yuesong Li <jake.yuesong@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

test/fixtures/test-runner/coverage/index.test.js

@@ -1,7 +1,7 @@
 'use strict';
 
 const test = require('node:test');
-test('no soucre map', () => {});
+test('no source map', () => {});
 if (false) {
   console.log('this does not execute');
 }