Anchor nav links don't show focus indicator on click on Safari

[GCHQ-Developer-847]

Summary of the bug

The links on the anchor navigation component on the website don't show the focus indicator on click on Safari, like it does on Chrome.

🪜 How to reproduce

1. On Safari, go to a page on the website which has an anchor nav on the right, e.g. the Accordion guidance page.
2. Click on one of the links on the anchor nav.
3. See that the focus indicator does not appear on click, whereas it does on Chrome.

🖥 📱 Device

• Browser: Safari

🧐 Expected behaviour

It should probably show the focus indicator as the behaviour isn't consistent with Chrome. The focus indicator is generally shown on click elsewhere, e.g. on the components.

[GCHQ-Developer-718]

Likely to have been fixed here.