"Change Email Address" requires a password, but not all users have one

[rolodato]

How are you running Flagsmith

• Self Hosted with Docker
• Self Hosted with Kubernetes
• SaaS at flagsmith.com
• Some other way (add details in description below)

Describe the bug

In the account settings, we provide an option for users to change their email address, which requires a password to confirm the change. When using Google, GitHub or SSO for login, users do not have a Flagsmith password so this functionality cannot be used.

Steps To Reproduce

1. Go to https://app.flagsmith.com/account as a GitHub, Google or SSO user
2. Click on "Change Email Address"
3. A password is prompted, but none exists

Expected behavior

Either disable this option for users without passwords, or provide some mechanism for users to actually change their email address.

Optionally, it would be nice to have some indication of the user's auth_type in this same setings menu, to remind the user of what they've used to log in in the past.

Screenshots

No response

[matthewelwell]

Related PR for a similar change to delete account: #3693