message: Allow intentionally null NumberInput value
  E.g. for specifying placeholders without providing a default value.
diff: @@ -60,7 +60,7 @@ function useNumberInput({
  isInvalid,
  isDisabled,
  }) {
  - const { current: isControlled } = useRef(valueProp != null);
  + const { current: isControlled } = useRef(valueProp !== undefined);
  const defaultPrecision = Math.max(calculatePrecision(stepProp), 0);
  const precision = precisionProp || defaultPrecision;
  @@ -216,13 +216,13 @@ function useNumberInput({
  onChange: handleChange,
  onKeyDown: handleKeyDown,
  ref: inputRef,
  - value: _value,
  + value: _value != null ? _value : undefined,
  role: "spinbutton",
  type: "text",
  "aria-valuemin": min,
  "aria-valuemax": max,
  "aria-disabled": isDisabled,
  - "aria-valuenow": _value,
  + "aria-valuenow": _value != null ? _value : undefined,
  "aria-invalid": isInvalid || isOutOfRange,
  ...(getAriaValueText && { "aria-valuetext": ariaValueText }),
  readOnly: isReadOnly,
  