[red-knot] Lookup of `__new__` (#17733)
## Summary
Model the lookup of `__new__` without going through
`Type::try_call_dunder`. The `__new__` method is only looked up on the
constructed type itself, not on the meta-type.
This now removes ~930 false positives across the ecosystem (vs 255 for
https://github.com/astral-sh/ruff/pull/17662). It introduces 30 new
false positives related to the construction of enums via something like
`Color = enum.Enum("Color", ["RED", "GREEN"])`. This is expected,
because we don't handle custom metaclass `__call__` methods. The fact
that we previously didn't emit diagnostics there was a coincidence (we
incorrectly called `EnumMeta.__new__`, and since we don't fully
understand its signature, that happened to work with `str`, `list`
arguments).
closes #17462
## Test Plan
Regression test
