SplitButton: menu item is using 'aria-level' attribute incorrectly

[ppc-harmoney]

Describe the bug

We are using prime ng in an application that is legally required to be WCAG compliant. To check compliance we are using Axe devtools.

It appears that the menu items for the split button are not setting the correct aria attributes, as we are seeing this error:
ARIA attribute is not allowed: aria-level="1"

Environment

Windows 11 Pro

Reproducer

No response

Angular version

16.2.9

PrimeNG version

16.9.1

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

18.18.2

Browser(s)

chrome 123

Steps to reproduce the behavior

Open the menu of a splitbutton and run a scan using axe devtools.

Expected behavior

I'm not entirely sure if the attribute should be corrected or removed, but axe devtool should not indicate it as a problem.