Fixed crash where the OpenAPI atomic:operations discriminator key isn't unique per schema ID

[bkoelman]

Use case:

[Resource]
public sealed class JigsawPuzzlePicture : Identifiable<long>;

[Resource]
public sealed class JigsawPuzzle : Identifiable<long>
{
    [HasOne]
    public required JigsawPuzzlePicture Picture { get; set; }
}

QUALITY CHECKLIST

• Changes implemented in code
• Complies with our contributing guidelines
• Adapted tests
• N/A: Documentation updated

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.04%. Comparing base (9277256) to head (b960dda).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1776      +/-   ##
==========================================
- Coverage   92.04%   92.04%   -0.01%     
==========================================
  Files         475      475              
  Lines       14736    14724      -12     
  Branches     2332     2331       -1     
==========================================
- Hits        13564    13552      -12     
  Misses        770      770              
  Partials      402      402              

☔ 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.