deck file openapi2kong broken for swagger 2.0

[io-timeout]

As of version 1.39.5 deck file openapi2kong fails to process swagger 2.0 specifications. This was working in 1.39.4 and prior. This is still broken in 1.40.3.

The error reported is:

2024/10/09 10:40:16 "msg"="error while building v3 document model \n" "error"="unable to build openapi document, supplied spec is a different version (oas2). Try 'BuildV2Model()'"
Error: failed converting OpenAPI spec 'petstore.yaml'; cannot create v3 model from document: 1 errors reported

(Tested using https://raw.githubusercontent.com/OAI/OpenAPI-Specification/refs/heads/main/examples/v2.0/yaml/petstore-expanded.yaml)