fix(userProfile): update email validation in controller

[Mahitha-pasupuleti]

Description

This PR fixes an issue in the user profile email update flow where the email update logic was not correctly handled in the backend controller.

Fixes # email update validation inconsistency in user profile update API.

Related PRS (if any):

This PR is a standalone backend fix. No dependent frontend PR required.

Main changes explained:

• Update file src/controllers/userProfileController.js for including new pattern
• Fixed email validation/update logic to ensure proper handling of updated email values
• Ensured consistent payload handling during user profile update request

How to test:

1. check into current branch: git checkout feature/volunteer-fix-email-update
2. do npm install and npm run dev to run this PR locally
3. Log in as a volunteer/user
4. Go to profile update section
5. Update email and save changes
6. Verify function:
   • Email updates successfully
   • No validation errors
   • Response reflects updated email correctly

Screenshots or videos of #[changes:]

Screen.Recording.2026-06-17.at.10.49.09.AM.mov

Note:

This is a small backend fix focused only on email update behavior in the user profile controller. Please verify API response consistency and validation behavior during review.