Gravatar switched to sha-256 and authentik is still usig md5

### Describe the bug

When using the gravatar option for avatars settings under System>Settings, Authentik hash the user email with md5 and then try to fetch https://gravatar.com/avatar/{email_has}

And due to md5 being vulnerable to collision attack, gravatar switched to sha-256 hashing

However, Authentik is still trying to use the md5 hash of the email address to fetch the avatac image

### How to reproduce

1. Hash your email in md5
2. Go to https://gravatar.com/site/check and type your email
3. Watch gravatar giving you a different hash

### Expected behavior

Athentik should fetch the gravatar url with the sha-256 of the user email

### Screenshots

### Additional context

_No response_

### Deployment Method

Docker

### Version

2025.10.3

### Relevant log output

```shell

```