fix(audit): not implemented for pnpm error

packages/@vue/cli-ui/ui-defaults/utils/audit.js

@@ -1,4 +1,4 @@
-const { hasProjectYarn, execa } = require('@vue/cli-shared-utils')
+const { hasProjectYarn, hasProjectPnpm, execa } = require('@vue/cli-shared-utils')
 
 const severity = {
   critical: 0,
@@ -107,6 +107,15 @@ exports.auditProject = async function (cwd) {
         status,
         details
       }
+    } else if (hasProjectPnpm(cwd)) {
+      // TODO pnpm audit
+      return {
+        status: {
+          status: 'error',
+          message: 'Not implemented for PNPM projects yet'
+        },
+        details: null
+      }
     } else {
       // TODO NPM audit
       return {