[Schema Inaccuracy] (GHES 3.18) organization_copilot_seat_management property on the app-permissions schema is missing read

Locate the app-permissions schema used by the organization installations endpoint and inspect the organization_copilot_seat_management property. Compare it with the documented GHES 3.18 response example, add the missing valid value, and run the repository's schema validation or relevant tests to confirm the response is representable.

Schema Inaccuracy

The organization_copilot_seat_management property on the app-permissions schema is missing read from its enum values for GHES 3.18.

Expected

The organization_copilot_seat_management property on the app-permissions schema should include read as a valid enum value:

  "organization_copilot_seat_management": {                                                                                         
    "type": "string",                                       
    "enum": ["read", "write"]
  }

Currently the schema only lists:

  "organization_copilot_seat_management": {                                                                                         
    "type": "string",                                       
    "enum": ["write"]
  }

Reproduction Steps

List app installations for an organization that has GitHub Copilot Business. Some installations will have
"organization_copilot_seat_management": "read" in their permissions object, which is not representable by the current schema.

  curl -H "Authorization: Bearer $GITHUB_TOKEN" \           
       -H "Accept: application/vnd.github+json" \                                                                                   
       https://ghes.example.com/api/v3/orgs/{org}/installations

Example response snippet:

  {                                                         
    "installations": [
      {
        "permissions": {
          "organization_copilot_seat_management": "read"                                                                            
        }
      }                                                                                                                             
    ]                                                       
  }