[CT-1106] [Bug] Include py.typed in MANIFEST.in

[panasenco]

Is this a new bug in dbt-core?

• I believe this is a new bug in dbt-core
• I have searched the existing issues, and I could not find an existing issue for this bug

Current Behavior

Currently when developing a dbt adapter and installing dbt-core with pip, I get errors like the following when trying to run mypy:

error: Skipping analyzing "dbt.contracts.connection": module is installed, but missing library stubs or py.typed marker
error: Skipping analyzing "dbt.events": module is installed, but missing library stubs or py.typed marker

This is because the file py.typed is not included in the package uploaded to pypi.

Expected Behavior

No mypy errors when checking types of packages that depend on dbt-core

Steps To Reproduce

Create a file with the line import dbt.events
Run mypy on that file

Relevant log output

No response

Environment

- OS: Ubuntu
- Python: 3.10.4
- dbt: 1.1.1

Which database adapter are you using with dbt?

other (mention it in "Additional Context")

Additional Context

Writing a custom adapter for dbt

[dbeatty10]

Exciting that you are working on a custom database adapter @panasenco!

(Side note: you might find a bunch of helpful experts in the #adapter-ecosystem Slack channel if you aren't already subscribed there.)

Thanks for submitting this issue and the relevant pull request 👍