MyPy reports false error when using Concatenate with ParamSpec

[gandhis1]

I confirmed that this was a bug here: python/typing#1286

Here is the final code snippet: https://mypy-play.net/?mypy=master&python=3.10&gist=ecbe2855b2c84a0ed7e5820fae2da90b&flags=strict

I searched this GitHub for similar issues and everything I see seems to imply that PEP 612 is fully supported (older issues that reported bugs were closed).

[erictraut]

ParamSpec and Concatenate add many new considerations and edge cases for a type checker. It took me a long time to work out all of the issues in pyright's PEP 612 implementation, and every time a bug was reported I augmented our test suite. At this point, pyright's PEP 612 tests are pretty comprehensive. Mypy maintainers are welcome to leverage these tests if you find them helpful. They are located in this directory, and the individual files are named paramSpec*.py.

[gandhis1]

This is likely related to #11855

[gandhis1]

Closing this issue as it is redundant with #11855. I checked out the working branch from #14159 and confirmed it works successfully on the sample code in this PR.