fix(web-components): expose toggle checked state to screen readers

[sylvesterkaczmarek]

Summary of the changes

Fixes the accessibility semantics for toggle items in ic-popover-menu.

The toggle role and aria-checked state were applied to the ic-button host while keyboard focus and screen-reader interaction occur on its native button. This change forwards those semantics to the native focus target and keeps aria-checked synchronized as the item is toggled.

Regression coverage now verifies both unchecked and checked states on the focusable native button, with the snapshot updated for the corrected accessible DOM.

Related issue

Closes #4518

Validation

• Acceptance criteria reviewed against the implementation
• Focused unit regression coverage added
• Existing component API remains unchanged
• ARIA role and checked state are placed on the focusable control

[CLAassistant]

All committers have signed the CLA.

[github-actions]

Welcome 👋

Welcome to the ic-ui-kit repo, thank you for submitting a pull request!

How to contribute

Please read our CONTRIBUTING.md, which explains our ways of working and guidelines for contributions.

Code of Conduct

We'd appreciate it if you could read and abide by our Code of Conduct, as we wish to foster an inclusive and respectful community.

Targeting your pull request

We use develop rather than main as the base for contributions - please make sure your PR is targeting develop.

Signing the CLA

We require all contributors to sign our Contributor License Agreement (CLA) before we can accept a contribution. If you are contributing on behalf of an organization please follow your organization's policies in signing CLAs.

Associated issue

Please make sure that your pull request has an issue open - this allows us to keep track of changes made and offer support where needed.

[GCHQ-Developer-530]

Hi @sylvesterkaczmarek, looks like this pull request is just failing prettier checks, please could you run npm run prettier:fix?

[sylvesterkaczmarek]

Thanks for flagging this. I've applied the formatting fix and pushed the update.

[GCHQ-Developer-530]

Hi, sorry it's now failing some unit tests. One of them appears to be a snapshot that can be regenerated, but another looks like an unexpected change to functionality. Would you be able to take a look into it?

[sylvesterkaczmarek]

Thanks for flagging this. I’ve pushed the Prettier-only formatting fix. The new workflow run is currently marked “action required”, so it looks like it now just needs maintainer approval before the checks can run.

[GCHQ-Developer-530]

Please rebase this branch