Fix crash for consider-using-assignment-expr

Author: zenlyj

doc/whatsnew/fragments/10707.bugfix

@@ -0,0 +1,4 @@
+Fix crash for ``consider-using-assignment-expr`` when a variable annotation without assignment
+is used as the ``if`` test expression.
+
+Closes #10707

pylint/extensions/code_style.py

@@ -272,6 +272,10 @@ def _check_consider_using_assignment_expr(self, node: nodes.If) -> None:
         if CodeStyleChecker._check_prev_sibling_to_if_stmt(
             prev_sibling, node_name.name
         ):
+            # Should ignore variable annotation without assignment
+            if prev_sibling.value is None:
+                return
+
             # Check if match statement would be a better fit.
             # I.e. multiple ifs that test the same name.
             if CodeStyleChecker._check_ignore_assignment_expr_suggestion(

tests/functional/ext/code_style/cs_consider_using_assignment_expr.py

@@ -157,3 +157,8 @@ class A:
 A.var = 2
 if A.var:
     ...
+
+
+i: int
+if i:  # pylint: disable=used-before-assignment
+    pass