Openapi document has the wrong version in the v0.37.x branch

The `version` property should be `v0.37` instead of `main` in the `v0.37.x branch`

https://github.com/cometbft/cometbft/blob/f1ce1c53f74e6c0c8683d7ed545407ef900b5a33/rpc/openapi/openapi.yaml#L54

The `v0.34` document shows it correctly 

https://github.com/cometbft/cometbft/blob/892516a63a0f39ea2e22dd0fe2405b8f13b7c22c/rpc/openapi/openapi.yaml#L54