TreeNode: Issue Title

[MichaelSagel]

Describe the bug

TreeNode ignores "node.selectable === false" with selectionMode checkbox

https://github.com/primefaces/primevue/blob/3923edff54d789946d39c815d45974123d709bff/components/lib/tree/TreeNode.vue#L142

this means if item should not be selected - it still will be selected

Reproducer

https://github.com/primefaces/primevue/blob/3923edff54d789946d39c815d45974123d709bff/components/lib/tree/TreeNode.vue#L142

PrimeVue version

3.49.0

Vue version

3.x

Language

TypeScript

Build / Runtime

Vite

Browser(s)

No response

Steps to reproduce the behavior

in description

Expected behavior

if node.selectable is false - it should not be selectable