[red-knot] Avoid panic for generic type aliases (astral-sh#14312)

## Summary

This avoids a panic inside `TypeInferenceBuilder::infer_type_parameters`
when encountering generic type aliases:
```py
type ListOrSet[T] = list[T] | set[T]
```

To fix this properly, we would have to treat type aliases as being their own
annotation scope [1]. The left hand side is a definition for the type parameter
`T` which is being used in the special annotation scope on the right hand side.
Similar to how it works for generic functions and classes.

[1] https://docs.python.org/3/reference/compound_stmts.html#generic-type-aliases


closes astral-sh#14307

## Test Plan

Added new example to the corpus.

crates/red_knot_python_semantic/src/types/infer.rs

@@ -1796,14 +1796,13 @@ impl<'db> TypeInferenceBuilder<'db> {
         let ast::StmtTypeAlias {
             range: _,
             name,
-            type_params,
+            type_params: _,
             value,
         } = type_alias_statement;
         self.infer_expression(value);
         self.infer_expression(name);
-        if let Some(type_params) = type_params {
-            self.infer_type_parameters(type_params);
-        }
+
+        // TODO: properly handle generic type aliases, which need their own annotation scope
     }
 
     fn infer_for_statement(&mut self, for_statement: &ast::StmtFor) {

crates/red_knot_workspace/resources/test/corpus/89_type_alias.py

@@ -1 +1,2 @@
 type foo = int
+type ListOrSet[T] = list[T] | set[T]