[4.3][bug] Refresh list of parent menu items after menu selection has been changed

[SniperSister]

Pull Request for Issue #38792

Summary of Changes

This patch correctly refreshes the list of available parent menu item after the actual menu assignment has been changed. This prevents an incorrect configuration (parent menu item selected which does not belong to the selected menu) being stored.

Testing Instructions

• Creata a J4 site with at least two menus and at least one menu item each
• Change the menu assignment of one menu item
• Check the available options in the parent menu item select

Actual result BEFORE applying this Pull Request

Parent menu select shows menu items of the old menu assignment.

Expected result AFTER applying this Pull Request

Parent menu select shows menu items of the new menu assignment.

Link to documentations

• No documentation changes for docs.joomla.org needed
• No documentation changes for manual.joomla.org needed

[chmst]

I have tested this item ✅ successfully on ad1c257

---

_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/39659.}

[viocassel]

I have tested this item ✅ successfully on ad1c257

---

_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/39659.}

[Quy]

RTC

---

_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/39659.}

[obuisard]

Thank you David @SniperSister for the bug fix!