fix(jump-links): landmark label

[bennypowers]

Closes #2860

What I did

1. add aria-labelledby="label" to the nav landmark element

Testing Instructions

1. confirm that screen readers read the page correctly

Notes to Reviewers

1. Note that the listbox is already labelled by the same element.

[changeset-bot]

🦋 Changeset detected

Latest commit: a8397ef

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

This PR includes changesets to release 1 package

Name	Type
@patternfly/elements	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

[github-actions]

✅ Commitlint tests passed!

More Info

{
  "valid": true,
  "errors": [],
  "warnings": [],
  "input": "fix(jump-links): landmark label"
}

[netlify]

✅ Deploy Preview for patternfly-elements ready!

Name	Link
🔨 Latest commit	3a5d314
😎 Deploy Preview	https://deploy-preview-2870--patternfly-elements.netlify.app/

---

To edit notification comments on pull requests, go to your Netlify site settings.

[github-actions]

SSR Test Run for af81208: Report

[adamjohnson]

Noticed you assigned this to Greg and I. Was that intentional or did you want us to be reviewers?

Happy to take this up if applicable.

[github-actions]

SSR Test Run for 9c8154f: Report