p-tree: Unselectable children is selected when selecting parent

[LouLeGrain]

Describe the bug

If a node with a disabled children is selected and propagateSelectionDown is true by default, then the unselectable children are selected, without possibility to unselect them.

Enregistrement.de.l.ecran.2024-09-25.a.11.48.00.mov

Environment

Angular ^17.3.6 / PrimeNG ^17.18.0

Reproducer

https://stackblitz.com/edit/github-fos6jj?file=src%2Fapp%2Fapp.component.ts

Angular version

^17.3.6

PrimeNG version

^17.18.0

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

18.20.3

Browser(s)

No response

Steps to reproduce the behavior

1. Create a p-tree component with a node that has an unselectable children
2. select parent node
3. unselectable children node is selected

Expected behavior

Unselectable treenode should be unselectable, even when selecting parent node

[SuRaMoN]

This fix causes nodes to be unselectable when nodes do not have a key.

example:
https://stackblitz.com/edit/github-fos6jj-ljajyw?file=src%2Fapp%2Fapp.component.ts

Screen recording (i'm clicking the nodes, but they dont get selected):

If you remove the keys sicne this fix selection does not work, with keys, it does work.

Reason is that since this fix we are cloning nodes:

But without keys we do a full contents comparison that always fails:

[SuRaMoN]

i submitted a new issue for this: #16819