This pull request fixes the bug described in issue
[#19153](https://github.com/astral-sh/ruff/issues/19153).
The issue occurred when `PERF403` incorrectly flagged cases involving
tuple unpacking in a for loop. For example:
```python
def f():
v = {}
for (o, p), x in [("op", "x")]:
v[x] = o, p
```
This code was wrongly suggested to be rewritten into a dictionary
comprehension, which changes the semantics.
Changes in this PR:
Updated the `PERF403` rule to correctly handle tuple unpacking in loop
targets.
Added regression tests to ensure this case (and similar ones) are no
longer flagged incorrectly.
Why:
This ensures that `PERF403` only triggers when a dictionary
comprehension is semantically equivalent to the original loop,
preventing false positives.
---------
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>