v3.21.0

Improvements

• [openapi-generator] Update generation of properties with nullable: true in the spec to include type | null in the output types. (d2a2394)
• [openapi-generator] Normalize schemas that have allOf, anyOf, or oneOf alongside properties defined at the same level. (d2a2394)
• [openapi-generator] Configure generated OpenAPI clients to handle text/plain, application/octet-stream, and wildcard */* content types in response headers. (89f77cd)