Rust: fix <X as Y> path extraction

This works around a quirk in rust-analyzer's AST generation machinery,
where for an `<X as Y>` path there might be no way to directly get `Y`
from the path segment.

rust/schema/ast.py

@@ -492,10 +492,8 @@ class PathSegment(AstNode, ):
     generic_arg_list: optional["GenericArgList"] | child
     name_ref: optional["NameRef"] | child
     parenthesized_arg_list: optional["ParenthesizedArgList"] | child
-    path_type: optional["PathTypeRepr"] | child
     ret_type: optional["RetTypeRepr"] | child
     return_type_syntax: optional["ReturnTypeSyntax"] | child
-    type_repr: optional["TypeRepr"] | child
 
 class PathTypeRepr(TypeRepr, ):
     path: optional["Path"] | child