React Dashboard: Fix focusTrap import

[ockham]

Changes proposed in this Pull Request:

One of the build errors when attempting to upgrade the @automattic/calypso-build dependency to v6.3.0 (#16845) is that the focus-trap npm module doesn't have a default export symbol. (This is confirmed by its docs.)

I assume that we're relying on a Babel plugin to add those default exports (mostly for CommonJS backwards compatibility), and the new calypso-build version would drop it. However, it even seems like focus-trap's API has long changed, so the current approach probably doesn't really work anyway (and just fails silently, since it's wrapped in try...catch calls).

Some more context:

• focusTrap was first introduced by Osk in Admin Page: Remove dops-components as dependency #8208 (as part of the big PR that brought dops-components into JP). At the time, the focus-trap version used per package.json was ^2.3.1.
• CommonJS requires were updated to ESM imports by yours truly in Dashboard: Migrate CommonJS require()s to ESM imports #11677.
• The breaking focus-trap API change apparently happened in v6.0.0.
• JP was updated to use that version in Update dependency focus-trap to v6 #17516 (about a month ago).

Jetpack product discussion

N/A

Does this pull request change what data or activity we track or use?

Nah.

Testing instructions:

I don't really know what this does 😬

Proposed changelog entry for your changes:

React Dashboard: Fix focusTrap import.

[jetpackbot]

Scheduled Jetpack release: January 12, 2021.
Scheduled code freeze: January 4, 2021

Thank you for the great PR description!

When this PR is ready for review, please apply the [Status] Needs Review label. If you are an a11n, please have someone from your team review the code if possible. The Jetpack team will also review this PR and merge it to be included in the next Jetpack release.

Generated by 🚫 dangerJS against 2edf130

[jeherve]

This seems to test well for me. Good catch!

I don't really know what this does 😬

I tested this by going to Jetpack > Dashboard on a connected site, clicking on the link to manage the connection in the Connection section, and once the modal was opened I tried to click into the wp-admin navigation menu on the left. As long as the trap is active, your clicks there won't do anything.

[ockham]

Thanks @kraftbj for merging! I wasn't able to do so earlier b/c the PHP 8.0 lint (which is clearly unrelated) blocked it for me 😅

[kraftbj]

All good. PHP 8 shouldn't have been a blocking check, but in either case, we should have some more PHP 8 joy landed pretty soon (the prod code is fine, we think, but the testing infra needed a bit to work).

[anomiex]

The PHP 8 linting should be blocking, IMO, since we're currently passing it and we don't want to regress. The problem wasn't actually in PHP 8 anyway, it's what we were discussing earlier at p1606835667387400-slack-CBG1CP4EN.