Is your feature request related to a problem? Please describe.
Currently, when using Renovate bot to manage Docker image updates for authentik, the bot cannot automatically fetch and display changelog information in pull requests. This makes it harder to understand what changes are included in new versions without manually checking the GitHub releases page.

Describe the solution you'd like
Add the following label to all authentik Docker images (Dockerfile, ldap.Dockerfile, proxy.Dockerfile, rac.Dockerfile, radius.Dockerfile):

LABEL org.opencontainers.image.source="https://github.com/goauthentik/authentik"

This OCI standard label allows tools like Renovate to automatically discover the source repository and fetch changelog information when creating update PRs. This is particularly useful for users who rely on automated dependency management.

Describe alternatives you've considered
Manually checking the GitHub releases page for each update (current workflow, time-consuming)
Configuring Renovate with custom package rules to manually specify the source URL (requires configuration on each user's side)
Using label during the build and push process
Using the org.opencontainers.image.source label is the standard approach adopted by many projects (Chainguard images, etc.) and requires no additional user configuration

Additional context
According to Renovate documentation, the Docker datasource looks for the org.opencontainers.image.source label to find the source repository and display changelogs in update PRs. This is a standard OCI image annotation that improves the developer experience for all users relying on automated dependency updates.

Reference: https://docs.renovatebot.com/modules/datasource/docker/