Feedback plugin - Users without email breaking all of the backend part and backstage fully crashes

[jonatanask]

Describe the bug

https://github.com/janus-idp/backstage-plugins/tree/main/plugins/feedback#readme
https://github.com/janus-idp/backstage-plugins/tree/main/plugins/feedback-backend

When imported users from gitlab doesn't have emails because their accounts are private, the system fully crashes and backstage stops working

TypeError: Cannot read properties of undefined (reading 'email') at /app/node_modules/@janus-idp/backstage-plugin-feedback-backend/dist/cjs/plugin-DV3-jMW_.cjs.js:375:160 at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

Expected Behavior

If there is no email, just don't send email. Or possibility to not send emails and to not use jira, so possibility to just create feedbacks in database

What are the steps to reproduce this bug?

1. When creating user kind, do not add email

apiVersion: backstage.io/v1alpha1
kind: User
metadata:
  name: guest
spec:
  memberOf: [guests]
  profile:
    displayName: Guest

2. Create a feedback with guest user

[yashoswalyo]

Fixed issue for user entities having no email property