[EuiSelectable][A11y] Search input is not read out by screen readers

[jorgeoliveira117]

Summary

Why are we making this change?

Screenshots #

Impact to users

QA

Remove or strikethrough items that do not apply to your PR.

General checklist

• Browser QA
  • Checked in both MacOS and Windows high contrast modes
    • (emulate forced colors if you do not have access to a Windows machine.)
  • Checked in mobile
  • Checked in Chrome, Safari, Edge, and Firefox
  • Checked for accessibility including keyboard-only and screenreader modes
• Code quality checklist
  • Added or updated jest and cypress tests
• Release checklist
  • A changelog entry exists and is marked appropriately
  • If applicable, added the breaking change issue label (and filled out the breaking change checklist)
  • If the changes unblock an issue in a different repo, smoke tested carefully (see Testing EUI features in Kibana ahead of time)

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 59d3bd4
• Documentation website
• Storybook

[elasticmachine]

💔 Build Failed

• Buildkite Build
• Commit: 59d3bd4

Failed CI Steps

• 🔨 EUI pull request test