private O doStaticEvaluate() {
    return ConfigExpressionScript.parse(scriptText, descriptor.root().description(), returnType)
      .apply(descriptor.root());
  }
Attempts to parse and evaluate this script in an environment with no variables.
<p>
If this returns {@link Try.Success} then it means this script will always return the same constant value and we can
avoid evaluating it at runtime.
planetiler-custommap/src/main/java/com/onthegomap/planetiler/custommap/expression/ConfigExpressionScript.java