[Bug]: Validation issue in profile picture input

[777Prabhjot]

Describe

There is no validation for profile picture input in sign up page right now i'll be able to upload any file format into it which may lead to backend error so i think there should be a validation for this field like only png, jpg, jpeg file format is allowed.

To reproduce

1. Go to SignUp page
2. Now try to upload any file format
3. See it's getting uploaded without any validation error

Screen Recording

bandicam.2023-07-31.09-41-30-811.mp4

### I Would Love to work on this issue under GSSOC23