Support for Atlassian OAuth-Provider

[backface]

Describe the feature or potential improvement

Could you add support for Atlassian Oauth Provider?

Should be easy as next-auth.js support it: https://next-auth.js.org/configuration/providers/oauth#built-in-providers

Additional information

No response

[marcklingen]

@backface thanks for sharing this idea! Open for a PR on this as this would be a great addition to Langfuse. Currently I'm a bit backlogged, otherwise I'd quickly add this myself