Fix Swagger/OpenAPI Schema

[kent-3]

This pull request addresses two issues in the swagger_legacy.yaml file:

• Corrected tyDeprecated: typos to type:
• Removed redundant object definition in the /reg/consensus-io-exch-pubkey endpoint response schema

Though part of the deprecated API, these errors were causing issues in the generated openapi.yaml and swagger.yaml files.

With these changes, the spec will now pass validation used by the OpenAPI Generator tool when generating code.

[assafmo]

Thanks! Looks good, I just want to see the CI building this before we merge