In the MCP integration, we should fix types and add py.typed, according to https://github.com/deepset-ai/haystack-core-integrations/issues/1771. Example PR for Bedrock: https://github.com/deepset-ai/haystack-core-integrations/pull/1912. I haven't done this yet because this integration is still experimental and subject to frequent changes (see for example #2004).
