Remove upper limit on Python version

[meshy]

This makes the library easier to install on projects managed by Poetry,
which would otherwise fail with an error like:

SolverProblemError

The current project's Python requirement (>=3.10,<4.0) is not compatible with some of the required packages Python requirement:
  - mypy-json-report requires Python >=3.7,<3.11, so it will not be satisfied for Python >=3.11,<4.0

Because mypy-json-report (0.1.2) requires Python >=3.7,<3.11
 and no versions of mypy-json-report match >0.1.2,<0.2.0, mypy-json-report is forbidden.
So, because $PROJECT_NAME depends on mypy-json-report (^0.1.2), version solving failed.

[meshy]

Thanks for the approval. It now looks like we're hitting an issue with a test dependency. sinoroc/tox-poetry-dev-dependencies#62

I'll get back to this.

[Tenzer]

The dependency problems should have been sorted out now. I have made #11 which removes the upper version boundary and adds Python 3.11 to the test matrix.

[meshy]

Thanks! I'll close this in favour of your PR.