Describe the bug

The merge of #3680 is very breaking. For example, it changes the OAS 3.0 component schema structure from:

"links": {
  "allOf": [
    {
      "$ref": "#/components/schemas/error-links"
    }
  ],
  "nullable": true
}

to:

"links": {
  "oneOf": [
    {
      "$ref": "#/components/schemas/error-links"
    },
    {
      "nullable": true
    }
  ]
}

It looks like the v10.0.2 release containing this change was retracted, but we build/test against the MyGet feed, which still contains this change. As a result, lots of our tests that assert on the output OAS structure are currently broken. Ignoring that, generating a C# client using Kiota against the changed files results in code that doesn't compile. Can the commit be reverted in the main branch as well?