test: log the location of ng/npm/yarn being tested

Author: jbedard

tests/legacy-cli/e2e/initialize/300-log-environment.ts

@@ -1,4 +1,4 @@
-import { ng } from '../utils/process';
+import { exec, ng } from '../utils/process';
 
 export default async function () {
   console.log('Environment:');
@@ -13,5 +13,6 @@ export default async function () {
     console.log(`  ${envName}: ${process.env[envName]!.replace(/[\n\r]+/g, '\n        ')}`);
   });
 
+  await exec('which', 'ng', 'yarn', 'npm');
   await ng('version');
 }