Deprecate/remove relaxed media types #1936
Description
Recent versions of kiota have already been fixed for the appearance of double quotes in media types. NSwag was fixed in RicoSuter/NSwag#5345.
Once NSwag has released a new version, the "relaxed" workaround is no longer needed. For compatibility, the .NET properties should be marked with [Obsolete], but the relaxed forms should be removed from the OpenAPI JSON:API extension spec.