test_runner: add junit file attribute support

Add file attribute to JUnit testcase elements when file information
is available in test event data.

Author: Han5991

lib/internal/test_runner/reporter/junit.js

@@ -116,6 +116,9 @@ module.exports = async function* junitReporter(source) {
         } else {
           currentTest.tag = 'testcase';
           currentTest.attrs.classname = event.data.classname ?? 'test';
+          if (event.data.file) {
+            currentTest.attrs.file = event.data.file;
+          }
           if (event.data.skip) {
             ArrayPrototypePush(currentTest.children, {
               __proto__: null, nesting: event.data.nesting + 1, tag: 'skipped',