feat(navigation) - add inert attribute to NavExpandable (patternfly#11749)

* feat(navigation) - add inert attribute to NavExpandable

* updated inert attribute value to empty string

* added two unit tests

* reworked the unit tests

Author: Mash707

packages/react-core/src/components/Nav/NavExpandable.tsx

@@ -141,7 +141,12 @@ class NavExpandable extends Component<NavExpandableProps, NavExpandableState> {
                 </button>
               )}
             </PageSidebarContext.Consumer>
-            <section className={css(styles.navSubnav)} aria-labelledby={this.id} hidden={expandedState ? null : true}>
+            <section
+              className={css(styles.navSubnav)}
+              aria-labelledby={this.id}
+              hidden={expandedState ? null : true}
+              {...(!expandedState && { inert: '' })}
+            >
               {srText && (
                 <h2 className="pf-v6-screen-reader" id={this.id}>
                   {srText}

packages/react-core/src/components/Nav/__tests__/Generated/__snapshots__/NavExpandable.test.tsx.snap

@@ -39,6 +39,7 @@ exports[`NavExpandable should match snapshot (auto-generated) 1`] = `
       aria-labelledby="''"
       class="pf-v6-c-nav__subnav"
       hidden=""
+      inert=""
     >
       <h2
         class="pf-v6-screen-reader"

packages/react-core/src/components/Nav/__tests__/NavExpandable.test.tsx

@@ -0,0 +1,15 @@
+import { render, screen } from '@testing-library/react';
+import '@testing-library/jest-dom';
+import { NavExpandable } from '../NavExpandable';
+
+test('Renders with the inert attribute by default', () => {
+  render(<NavExpandable id="grp-1" title="NavExpandable"></NavExpandable>);
+
+  expect(screen.getByLabelText('NavExpandable')).toHaveAttribute('inert', '');
+});
+
+test('Does not render with the inert attribute when isExpanded is true', () => {
+  render(<NavExpandable id="grp-1" title="NavExpandable" isExpanded={true}></NavExpandable>);
+
+  expect(screen.getByLabelText('NavExpandable')).not.toHaveAttribute('inert', '');
+});

packages/react-core/src/components/Nav/__tests__/__snapshots__/Nav.test.tsx.snap

@@ -223,6 +223,7 @@ exports[`Nav Expandable Nav List - Trigger toggle 1`] = `
           aria-labelledby="grp-1"
           class="pf-v6-c-nav__subnav"
           hidden=""
+          inert=""
         >
           <ul
             class="pf-v6-c-nav__list"
@@ -355,6 +356,7 @@ exports[`Nav Expandable Nav List 1`] = `
           aria-labelledby="grp-1"
           class="pf-v6-c-nav__subnav"
           hidden=""
+          inert=""
         >
           <ul
             class="pf-v6-c-nav__list"
@@ -486,6 +488,7 @@ exports[`Nav Expandable Nav List with aria label 1`] = `
           aria-labelledby="grp-1"
           class="pf-v6-c-nav__subnav"
           hidden=""
+          inert=""
         >
           <h2
             class="pf-v6-screen-reader"