Minor fix for build-relationships.py

[tmcgilchrist]

I discovered this while working on OCaml support for combobulate.

Running the codegen step for OCaml grammars results in invalid syntax for rules in combobulate-rules.el. Some of the rules e.g. _signed_constant don't produce quoted strings.

...
 (_signed_constant (:*unnamed* ("signed_number" "unit" "character" "quoted_string" "string" "number" "boolean"))) 
 (_simple_class_expression (:*unnamed* ("class_path" "typed_class_expression" "parenthesized_class_expression" "extension" "quoted_extension" "object_expression" "instantiated_class"))) 
 ...

Using these versions of the OCaml treesitter grammar:

nodes = https://raw.githubusercontent.com/tree-sitter/tree-sitter-ocaml/v0.24.0/grammars/ocaml/src/node-types.json
grammar = https://raw.githubusercontent.com/tree-sitter/tree-sitter-ocaml/v0.24.0/grammars/ocaml/src/grammar.json

I also needed this same fix for Rust and Haskell grammars.

[mickeynp]

Thanks for contributing!