FIX calendar picker if weeknumbers hidden and time format 24h

[cyrez]

Pull Request for Issue introduced (by me 🥇 ) in PR #40761.

Affected Joomla versions: 4.4.0 and 5.0.0

Summary of Changes

Quick FIX
Check if weeknumbers is true or false to listen to correct number of childNodes.
Calendar form field with 12h (AM/PM) time format is not affected by the issue, as well as calendar picker with week numbers (so Joomla core not affected).

Testing Instructions

Set 2 form fields of type calendar like this (with and without week numbers):

Note: default timeformat is 24 and dedault weeknumbers is true.

<field
	name="no_week_numbers"
	type="calendar"
	label="Test"
	description="Test without weeknumbers and time 24h"
	showtime="true"
	weeknumbers="false"
/>

<field
	name="week_numbers"
	type="calendar"
	label="Test"
	description="Test with weeknumbers and time 24h"
	showtime="true"
/>

Actual result BEFORE applying this Pull Request

You can't change Time (hour and/or minutes) with the no_week_numbers calendar picker.
It's working with the other form field.

Expected result AFTER applying this Pull Request

It's working in both cases.

Link to documentations

Please select:

• Documentation link for docs.joomla.org:

• No documentation changes for docs.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed

Actual result BEFORE applying this Pull Request

Expected result AFTER applying this Pull Request

Link to documentations

Please select:

• Documentation link for docs.joomla.org:

• No documentation changes for docs.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed