test: clean up test/parallel/test-runner-coverage-source-map.js

Co-authored-by: Moshe Atlow <moshe@atlow.co.il>

Author: geeksilva97

test/parallel/test-runner-coverage-source-map.js

@@ -45,7 +45,7 @@ describe('Coverage with source maps', async () => {
     t.assert.strictEqual(spawned.code, 1);
   });
 
-  await it.only('accounts only mapped lines when --enable-source-maps is provided', async (t) => {
+  it('accounts only mapped lines when --enable-source-maps is provided', async (t) => {
     const report = generateReport([
       '# --------------------------------------------------------------',
       '# file          | line % | branch % | funcs % | uncovered lines',