fix(deps): update dependency ty to v0.0.20

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
ty (changelog)	==0.0.19 → ==0.0.20

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Release Notes

astral-sh/ty (ty)

v0.0.20

Compare Source

Released on 2026-03-02.

Bug fixes

• Disallow negative narrowing for isinstance() or issubclass() checks involving type[] types (#​23598)
• Fix binary operations between an instance of a NewType of float and an instance of Any/Unknown (#​23620)
• Fix bug where ty would think that a Callable with a variadic positional parameter could be a subtype of a Callable with a positional-or-keyword parameter (#​23610)
• Fix inference of t.__mro__ if t is an instance of type[Any] (#​23632)
• Fix overloaded callable assignability for unary Callable targets (#​23277)
• Limit recursion depth when displaying self-referential function types (#​23647)
• Ensure that python -m ty works even when ty was installed into an ephemeral virtual environment (#​2852)

LSP server

• Add support for the LSP protocol's "type hierarchy" feature (#​23566)

Type checking

• Add more ParamSpec validation for P.args and P.kwargs (#​23640)
• Ban nested Required/NotRequired, and ban them both outside of TypedDict fields (#​23627)
• Detect inconsistent generic base class specializations that appear in the same MRO (#​23615)
• Detect invalid uses of @final on non-methods (#​23604)
• Add partial support and validation for Unpack when used with tuple types (#​23651)
• Recurse into tuples and nested tuples when applying special-cased validation of arguments passed to isinstance() and issubclass() (#​23607)
• Reject ellipsis literals in odd places in type/annotation expressions (#​23611)
• Reject functions with PEP-695 type parameters that shadow type parameters from enclosing scopes (#​23619)
• Reject generic metaclasses parameterized by type variables (#​23628)
• Treat dataclass_transform dataclasses as neither frozen nor non-frozen (#​23366)
• Validate that type variable defaults don't reference later type parameters or type parameters out of scope (#​23623)

Typeshed

• Sync vendored typeshed stubs (#​23642). Typeshed diff

Contributors

• @​Hugo-Polloli
• @​zanieb
• @​sharkdp
• @​mtshiba
• @​carljm
• @​charliermarsh
• @​sinon
• @​BurntSushi
• @​oconnor663
• @​AlexWaygood
• @​zsol

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.15%. Comparing base (3044354) to head (426107a).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1594   +/-   ##
=======================================
  Coverage   79.15%   79.15%           
=======================================
  Files         354      354           
  Lines       11658    11658           
  Branches      536      536           
=======================================
  Hits         9228     9228           
  Misses       2245     2245           
  Partials      185      185           

Flag	Coverage Δ
unittests	79.15% <ø> (ø)

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