Replace `pyyaml`

[chirizxc]

Summary

• pyyaml support only YAML 1.1 (OpenAPI Specification 3.1 says: YAML 1.2 version is RECOMMENDED)

• pyyaml does not throw an error when keys are duplicated:

unihttp-openapi-generator/examples/open_meteo/openapi.yaml

Lines 1 to 6 in 387daab

	openapi: 3.1.0
	info:
	title: Open-Meteo Forecast API
	version: "1.0.0"
	description: >-
	Free weather forecast API (https://open-meteo.com) — no API key required.

If we add:

  version: "1.0.0"
  version: "1.0.1"
  version: "1.0.2"

There won't be any errors

See also: ag2ai/faststream#2709

How replace?

• yaml-rs

• another lib, with full YAML 1.2 support