This is my first PR and I'm new at rust, so feel free to ask me to
rewrite everything if needed ;)
The rule must be called after deferred lambas have been visited because
of the last check (whether the lambda parameters are used in the body of
the function that's being called). I didn't know where to do it, so I
did what I could to be able to work on the rule itself:
- added a `ruff_linter::checkers::ast::analyze::lambda` module
- build a vec of visited lambdas in `visit_deferred_lambdas`
- call `analyze::lambda` on the vec after they all have been visited
Building that vec of visited lambdas was necessary so that bindings
could be properly resolved in the case of nested lambdas.
Note that there is an open issue in pylint for some false positives, do
we need to fix that before merging the rule?
https://github.com/pylint-dev/pylint/issues/8192
Also, I did not provide any fixes (yet), maybe we want do avoid merging
new rules without fixes?
## Summary
Checks for lambdas whose body is a function call on the same arguments
as the lambda itself.
### Bad
```python
df.apply(lambda x: str(x))
```
### Good
```python
df.apply(str)
```
## Test Plan
Added unit test and snapshot.
Manually compared pylint and ruff output on pylint's test cases.
## References
- [pylint
documentation](https://pylint.readthedocs.io/en/latest/user_guide/messages/warning/unnecessary-lambda.html)
- [pylint
implementation](https://github.com/pylint-dev/pylint/blob/main/pylint/checkers/base/basic_checker.py#L521-L587)
- https://github.com/astral-sh/ruff/issues/970
