Fix line number for slices, clean up old logic

[hauntsaninja]

Fixes #17655

The decorator cleanup moves a type ignore, but so does the bug fix for decorators in #18392 , so might as well batch into a single release

[hauntsaninja]

werkzeug seems good (hiding false negatives)
schemathesis seems good (hiding false negatives)
antidote is fine (also repo is archived)
homeassistant is confusing
trio is unfortunate. we should add a better error code for explicit any (which would require a change for them as well) (edit: #18398 )
pandas is unfortunate

Overall, I think we should merge. I can add a changelog entry though

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

pandas (https://github.com/pandas-dev/pandas)
+ pandas/core/arrays/period.py:378: error: Unused "type: ignore" comment  [unused-ignore]
+ pandas/core/arrays/period.py:379: error: Cannot override writeable attribute with read-only property  [override]

trio (https://github.com/python-trio/trio)
+ src/trio/_path.py:196: error: Unused "type: ignore" comment  [unused-ignore]
+ src/trio/_path.py:197: error: Explicit "Any" is not allowed  [misc]
+ src/trio/_path.py:197: error: Type of decorated function contains type "Any" ("Callable[[Path, VarArg(Any), KwArg(Any)], Awaitable[AsyncIOWrapper[IO[Any]]]]")  [misc]
+ src/trio/_tests/test_subprocess.py:85: error: Unused "type: ignore" comment  [unused-ignore]
+ src/trio/_tests/test_subprocess.py:86: error: Explicit "Any" is not allowed  [misc]
+ src/trio/_tests/test_subprocess.py:86: error: Type of decorated function contains type "Any" ("Callable[[VarArg(Any), KwArg(Any)], _AsyncGeneratorContextManager[Process]]")  [misc]
+ src/trio/_tests/test_subprocess.py:98: error: Unused "type: ignore" comment  [unused-ignore]
+ src/trio/_tests/test_subprocess.py:99: error: Explicit "Any" is not allowed  [misc]
+ src/trio/_tests/test_subprocess.py:99: error: Type of decorated function contains type "Any" ("Callable[[VarArg(Any), KwArg(Any)], _AsyncGeneratorContextManager[Process]]")  [misc]
+ src/trio/_core/_tests/test_ki.py:168: error: Function is untyped after decorator transformation  [misc]
+ src/trio/_core/_tests/test_ki.py:177: error: Function is untyped after decorator transformation  [misc]
+ src/trio/_core/_tests/test_ki.py:187: error: Function is untyped after decorator transformation  [misc]
+ src/trio/_core/_tests/test_ki.py:196: error: Function is untyped after decorator transformation  [misc]

core (https://github.com/home-assistant/core)
+ homeassistant/components/zha/device_tracker.py:64: error: Unused "type: ignore[explicit-override]" comment  [unused-ignore]

schemathesis (https://github.com/schemathesis/schemathesis)
+ src/schemathesis/cli/__init__.py:834: error: Unused "type: ignore" comment  [unused-ignore]
+ src/schemathesis/cli/__init__.py:864: error: Function is missing a type annotation for one or more arguments  [no-untyped-def]

antidote (https://github.com/Finistere/antidote)
+ tests/lib/lazy/test_lazy.py:293: error: Missing return statement  [empty-body]
+ tests/lib/lazy/test_lazy.py:301: error: Missing return statement  [empty-body]
+ tests/lib/lazy/test_lazy.py:308: error: Missing return statement  [empty-body]
+ tests/lib/interface/test_lazy.py:441: error: Missing return statement  [empty-body]
+ tests/lib/interface/test_lazy.py:447: error: Missing return statement  [empty-body]
+ tests/lib/interface/test_function.py:306: error: Missing return statement  [empty-body]
+ tests/lib/interface/test_function.py:312: error: Missing return statement  [empty-body]
+ tests/lib/interface/test_function.py:318: error: Missing return statement  [empty-body]
+ tests/lib/interface/test_function.py:324: error: Missing return statement  [empty-body]

werkzeug (https://github.com/pallets/werkzeug)
+ tests/test_exceptions.py:147: error: Function is missing a return type annotation  [no-untyped-def]
+ tests/test_exceptions.py:147: note: Use "-> None" if function does not return a value
+ tests/test_exceptions.py:167: error: Function is missing a return type annotation  [no-untyped-def]
+ tests/test_exceptions.py:167: note: Use "-> None" if function does not return a value