fix(providers): enable OIDC capabilities for Keycloak

[jvllmr]

☕️ Reasoning

Keycloak is an OpenID Connect provider, but it is only defined as an OAuth provider. Because of this OpenID capabilities such as using user data from the userinfo endpoint via the idToken configuration parameter are not available to users although keycloak could support them.

🧢 Checklist

• Documentation
• Tests
• Ready to be merged

🎫 Affected issues

📌 Resources

• Security guidelines
• Contributing guidelines
• Code of conduct
• Contributing to Open Source

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
auth-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	May 13, 2025 1:52am

1 Skipped Deployment

Name	Status	Preview	Comments	Updated (UTC)
next-auth-docs	⬜️ Ignored (Inspect)	Visit Preview		May 13, 2025 1:52am

[vercel]

@jvllmr is attempting to deploy a commit to the authjs Team on Vercel.

A member of the Team first needs to authorize it.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 39.18%. Comparing base (f39867a) to head (85a027b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/core/src/providers/keycloak.ts	0.00%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #12964   +/-   ##
=======================================
  Coverage   39.18%   39.18%           
=======================================
  Files         200      200           
  Lines       31612    31612           
  Branches     1380     1380           
=======================================
  Hits        12388    12388           
  Misses      19224    19224           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.