Stop proposing dependency floors this project cannot install

[DenisDrobyshev]

The dev-tooling group in #17 raised the mypy floor to 2.3.1, which requires Python ≥3.11:

ERROR: Could not find a version that satisfies the requirement mypy>=2.3.1; extra == "dev"
ERROR: Ignored the following versions that require a different python version:
       ... Requires-Python >=3.11 ...

CI tests 3.9 through 3.13. The py3.9 leg failed at install in 41 seconds, before a single test ran, while the other four passed in about three minutes each. Not a flake, and a re-run does not fix it — the floor cannot move until 3.9 is dropped, and that is a decision about the support matrix rather than about a linter.

update-types does not help, for the reason already written into lemma's configuration: for a >= constraint Dependabot files a requirement update, which that filter does not match. So the ignore is unconditional.

The other three

tqdm, onnx and onnxruntime are ignored for a different reason, and it is the one stated in lemma's config in your own words: a lower bound describes what a user may already have installed, not what CI resolves. pip takes the newest match either way, so raising the floor locks people out and changes nothing that gets tested.

All three are genuinely imported — this is not the praxis case where the dependency was unused. They should move when the code needs a newer API, not on a schedule.

Effect

Dependabot closes its own open PRs for a dependency once it becomes ignored, so #18, #20 and #21 should disappear on their own after this lands. #17 is already closed with the install log.

The existing entries — torch pinned outright, numpy and gymnasium majors — are untouched.