False positive in PERF402 when append is more complex.

[bgianfo]

The new rule PERF402 suggests to convert lists to trivial copies in cases where it's not really possible. Ideally the tool would not report such false positives.

If you're filing a bug report, please consider including the following information:

• A minimal code snippet that reproduces the bug.

 # In this example you can't trivially convert this to a `list.copy` as the rule suggests.  
 for r in record_dict["values"]:
        list_of_stuff[r["other_value"]].append(r)

• The command you invoked (e.g., ruff /path/to/file.py --fix), ideally including the --isolated flag.

  ruff --select=PERF402 example.py

• The current Ruff settings (any relevant sections from your pyproject.toml).

  PERF ruleset is enabled

• The current Ruff version (ruff --version).

  version = 0.0.276

[charliermarsh]

Makes sense, we should probably require that the left-hand side expression is a static name (or at least an expression that doesn't depend on the iteration key). Thanks!