fix: fix mcp types + add py.typed

[vblagoje]

Related Issues

• part of Investigate better typing configuration for core integrations #1771

Proposed Changes:

• run hatch run test:types and fix type errors
  (this means testing with all dependencies installed, differently from hatch run lint:typing that did not install dependencies)
• use hatch run test:types in the test workflow
• remove hatch run lint:typing
• introduce stricter configuration in pyproject.toml (and fix small errors)
• add py.typed to allows usage of types in downstream projects
  • as shown in feat: Chroma - fix typing + ship types by adding py.typed files #1910, these files should be put in submodules of the namespace packages
  • the namespace package is haystack_integrations
  • in this case, I put py.typed in
    • integrations/mcp/src/haystack_integrations/tools/mcp/py.typed
    • as a rule of thumb, py.typed files should be placed at the same level as the inner folder that corresponds to the integration name.

How did you test it?

CI

Notes for the reviewer

This PR can be seen as a complete example of the work we need to do for each integration to fix #1771.

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.

[davidsbatista]

LGTM

[anakin87]

Can we avoid adding mcp to ignore_missing_imports?
Otherwise, we'd end up not verifying MCP types at all

[vblagoje]

@anakin87 thanks for spotting this, see 0a873c8
Are we gtg now?

[anakin87]

Have you tried removing this block altogether?
If possible, it would be the best thing to do. But sometimes, libraries do not provide valid types, so it's not always doable.

[anakin87]

👏