E2E Tests: Run in Github Actions

[brbrr]

WIP

Changes proposed in this Pull Request:

Is this a new feature or does it add/remove features to an existing part of Jetpack?

• If you're an Automattician, include a shortlink to the p2 discussion with Jetpack Product here.

Testing instructions:

• Go to '..'

Proposed changelog entry for your changes:

[jetpackbot]

	Warnings
⚠️	pre-commit hook was skipped for one or more commits

This is an automated check which relies on PULL_REQUEST_TEMPLATE. We encourage you to follow that template as it helps Jetpack maintainers do their job. If you think 'Testing instructions' or 'Proposed changelog entry' are not needed for your PR - please explain why you think so. Thanks for cooperation 🤖

Generated by 🚫 dangerJS against b81bcc1

[stale]

This PR has been marked as stale. This happened because:

• It has been inactive in the past 3 months.
• It hasn’t been labeled `[Pri] Blocker`, `[Pri] High`.

No further action is needed. But it's worth checking if this PR has clear testing instructions, is it up to date with master, and it is still valid. Feel free to close this issue if you think it's not valid anymore — if you do, please add a brief explanation.

[brbrr]

closing in favor of #17094