Handle non-ascii characters when generating fuzzing dictionary
Handle non-ascii characters when generating fuzzing dictionary

This caused a failure when generating the dictionary for `tree-sitter-agda`.

tree-sitter/tree-sitter,tree-sitter/tree-sitter,tree-sitter/tree-sitter,tree-sitter/tree-sitter,tree-sitter/tree-sitter,tree-sitter/tree-sitter,tree-sitter/tree-sitter