fix: pinned wp/element to 4.8.0 until we sort out esm dependencies

[rjchow]

All Submissions:

• Have you followed the WooCommerce Contributing guideline?
• Does your code follow the WordPress' coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

Due to some upstream changes including a package that uses ESM, jest needs to transform such files before it can be run. Unfortunately at this point in time it is quite complicated and we will require more time to properly implement a fix.

More context at: p1660624973259689-slack-C03CPM3UXDJ

At this point in time we will just pin the @wordpress/element package at 4.8.0 across the entire repo, by using pnpm.overrides, so that we can still rely on unit tests.

How to test the changes in this Pull Request:

Purely a dev env change; Jest tests should pass both in CI and locally

1. Try commands such as git clean -fdx && pnpm i && pnpm run build && cd ./plugins/woocommerce-admin && pnpm run test
2. And also attempt to run tests within the packages themselves

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes, as applicable?
• Have you successfully run tests with your changes locally?
• Have you created a changelog file for each project being changed, ie pnpm changelog add --filter=<project>?

FOR PR REVIEWER ONLY:

• I have reviewed that everything is sanitized/escaped appropriately for any SQL or XSS injection possibilities. I made sure Linting is not ignored or disabled.

[chihsuan]

Thanks for the fix. Tested well locally and looks good! 👍