Fix use-sequence-for-iteration when unpacking a set with *.

Closes pylint-dev#5788

Author: clavedeluna

doc/whatsnew/fragments/5788.false_positive

@@ -0,0 +1,3 @@
+Fix ``use-sequence-for-iteration`` when unpacking a set with ``*``.
+
+Closes #5788

pylint/checkers/refactoring/recommendation_checker.py

@@ -333,8 +333,13 @@ def _check_consider_using_dict_items_comprehension(
     def _check_use_sequence_for_iteration(
         self, node: nodes.For | nodes.Comprehension
     ) -> None:
-        """Check if code iterates over an in-place defined set."""
-        if isinstance(node.iter, nodes.Set):
+        """Check if code iterates over an in-place defined set.
+
+        Sets using `*` are not considered in-place.
+        """
+        if isinstance(node.iter, nodes.Set) and not any(
+            isinstance(x, nodes.Starred) for x in node.iter.elts
+        ):
             self.add_message("use-sequence-for-iteration", node=node.iter)
 
     @utils.only_required_for_messages("consider-using-f-string")

tests/functional/ext/code_style/cs_consider_using_tuple.py

@@ -28,4 +28,4 @@
 
 # Don't emit warning for sets as this is handled by builtin checker
 (x for x in {1, 2, 3})  # [use-sequence-for-iteration]
-[x for x in {*var, 2}]  # [use-sequence-for-iteration]
+[x for x in {*var, 2}]

tests/functional/u/use/use_sequence_for_iteration.py

@@ -13,4 +13,12 @@
 [x for x in var]
 [x for x in {1, 2, 3}]  # [use-sequence-for-iteration]
 
-[x for x in {*var, 4}]  # [use-sequence-for-iteration]
+[x for x in {*var, 4}]
+
+def deduplicate(list_in):
+    for thing in {*list_in}:
+        print(thing)
+
+def deduplicate_two_lists(input1, input2):
+    for thing in {*input1, *input2}:
+        print(thing)

tests/functional/u/use/use_sequence_for_iteration.txt

@@ -1,4 +1,3 @@
 use-sequence-for-iteration:7:9:7:18::Use a sequence type when iterating over values:UNDEFINED
 use-sequence-for-iteration:11:12:11:21::Use a sequence type when iterating over values:UNDEFINED
 use-sequence-for-iteration:14:12:14:21::Use a sequence type when iterating over values:UNDEFINED
-use-sequence-for-iteration:16:12:16:21::Use a sequence type when iterating over values:UNDEFINED