fix(core/menu): use label property to render internal menu items

[danielleroux]

🆕 What is the new behavior?

Using slot for content results sometimes to empty tooltip within the menu, to avoid this use the label property.

🏁 Checklist

A pull request can only be merged if all of these conditions are met (where applicable):

• [ ] 🦮 Accessibility (a11y) features were implemented
• [ ] 🗺️ Internationalization (i18n) - no hard coded strings
• [ ] 📲 Responsiveness - components handle viewport changes and content overflow gracefully
• [ ] 📄 Documentation was reviewed/updated (pnpm run docs)
• [x] 🧪 Unit tests were added/updated and pass (pnpm test)
• [x] 📸 Visual regression tests were added/updated and pass (Guide)
• [x] 🧐 Static code analysis passes (pnpm lint)
• [x] 🏗️ Successful compilation (pnpm build, changes pushed)

👨‍💻 Help & support

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: fadbe55b2f7cb5ef712418f5209bd2334fefe600

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

| Name | Type | | ------------------- | ----- | | @siemens/ix | Patch | | @siemens/ix-angular | Patch | | @siemens/ix-react | Patch | | @siemens/ix-vue | Patch |

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR