Remove BindingKind::ComprehensionVar (#12347)

## Summary

This doesn't seem to be used anywhere. Maybe it mattered when we didn't
handle generator scopes properly?

crates/ruff_linter/src/checkers/ast/mod.rs

@@ -2009,16 +2009,6 @@ impl<'a> Checker<'a> {
             return;
         }
 
-        // If the expression is part of a comprehension target, then it's a comprehension variable
-        // assignment, as in:
-        // ```python
-        // [x for x in range(10)]
-        // ```
-        if self.semantic.in_comprehension_assignment() {
-            self.add_binding(id, expr.range(), BindingKind::ComprehensionVar, flags);
-            return;
-        }
-
         // Match the left-hand side of an annotated assignment without a value,
         // like `x` in `x: int`. N.B. In stub files, these should be viewed
         // as assignments on par with statements such as `x: int = 5`.

crates/ruff_linter/src/renamer.rs

@@ -264,7 +264,6 @@ impl Renamer {
             | BindingKind::Assignment
             | BindingKind::BoundException
             | BindingKind::LoopVar
-            | BindingKind::ComprehensionVar
             | BindingKind::WithItemVar
             | BindingKind::Global(_)
             | BindingKind::Nonlocal(_, _)

crates/ruff_linter/src/rules/pandas_vet/helpers.rs

@@ -47,7 +47,6 @@ pub(super) fn test_expression(expr: &Expr, semantic: &SemanticModel) -> Resoluti
                         | BindingKind::Assignment
                         | BindingKind::NamedExprAssignment
                         | BindingKind::LoopVar
-                        | BindingKind::ComprehensionVar
                         | BindingKind::Global(_)
                         | BindingKind::Nonlocal(_, _) => Resolution::RelevantLocal,
                         BindingKind::Import(import)

crates/ruff_linter/src/rules/pylint/rules/non_ascii_name.rs

@@ -56,7 +56,6 @@ pub(crate) fn non_ascii_name(binding: &Binding, locator: &Locator) -> Option<Dia
         BindingKind::Assignment => Kind::Assignment,
         BindingKind::TypeParam => Kind::TypeParam,
         BindingKind::LoopVar => Kind::LoopVar,
-        BindingKind::ComprehensionVar => Kind::ComprenhensionVar,
         BindingKind::WithItemVar => Kind::WithItemVar,
         BindingKind::Global(_) => Kind::Global,
         BindingKind::Nonlocal(_, _) => Kind::Nonlocal,
@@ -94,7 +93,6 @@ enum Kind {
     Assignment,
     TypeParam,
     LoopVar,
-    ComprenhensionVar,
     WithItemVar,
     Global,
     Nonlocal,
@@ -112,7 +110,6 @@ impl fmt::Display for Kind {
             Kind::Assignment => f.write_str("Variable"),
             Kind::TypeParam => f.write_str("Type parameter"),
             Kind::LoopVar => f.write_str("Variable"),
-            Kind::ComprenhensionVar => f.write_str("Variable"),
             Kind::WithItemVar => f.write_str("Variable"),
             Kind::Global => f.write_str("Global"),
             Kind::Nonlocal => f.write_str("Nonlocal"),

crates/ruff_python_semantic/src/binding.rs

@@ -467,12 +467,6 @@ pub enum BindingKind<'a> {
     /// ```
     LoopVar,
 
-    /// A binding for a comprehension variable, like `x` in:
-    /// ```python
-    /// [x for x in range(10)]
-    /// ```
-    ComprehensionVar,
-
     /// A binding for a with statement variable, like `x` in:
     /// ```python
     /// with open('foo.py') as x: