[EuiComboBox] Fix enter key not working correctly on selection clear/deletion buttons

[cee-chen]

Summary

closes https://github.com/elastic/eui/issues/8104 closes https://github.com/elastic/eui/issues/7289

QA

• Go to https://eui.elastic.co/pr_8105/storybook/?path=/story/forms-euicombobox--playground
• Tab to the X button next to the selected Item 1
• [x] Confirm that pressing the Enter key works to clear the item selection
• Select all items in the dropdown menu (arrow key and enter key to select items should still work as expected)
• Tab to the round X button
• [x] Confirm that pressing the Enter key clears all selected items

General checklist

• Browser QA ~- [ ] Checked in both light and dark modes~ ~- [ ] Checked in mobile~
  • [x] Checked in Chrome, Safari, Edge, and Firefox
  • [x] Checked for accessibility including keyboard-only ~and screenreader modes~
• Docs site QA - N/A
• Code quality checklist
  • [x] Added or updated ~jest and~ cypress tests ~- [ ] Updated visual regression tests~
• Release checklist
  • [x] A changelog entry exists and is marked appropriately. ~- [ ] If applicable, added the breaking change issue label (and filled out the breaking change checklist)~
• Designer checklist - N/A

[kibanamachine]

Preview staging links for this PR:

• Docs site: https://eui.elastic.co/pr_8105/
• Storybook: https://eui.elastic.co/pr_8105/storybook
• New docs: https://eui.elastic.co/pr_8105/new-docs

[elasticmachine]

:green_heart: Build Succeeded

• Buildkite Build
• Commit: e62f0dbd65d1a694acd46ef3db77f3086a36f180

History

• :broken_heart: Build #2980 failed 39c5d64aecdc56b20be08dc2ae24c29a912137c0

[cee-chen]

Thanks Lene!!