Packages: Remove unused @automattic/launch package and launch store

[tyxla]

Proposed Changes

This PR removes the unused automattic/launch store and the unused @automattic/launch package.

Part of #74399. A follow-up to #73890.

Testing Instructions

• Verify that the removed store is not in use.
• Verify the removed package is not in use.
• All checks should be green and Calypso should build well.

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-62514

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-62514&env=jetpack

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[matticbot]

This PR modifies the release build for editing-toolkit

To test your changes on WordPress.com, run install-plugin.sh editing-toolkit remove/launch-package on your sandbox.

To deploy your changes after merging, see the documentation: PCYsg-mMA-p2

[tyxla]

There are a few @automattic/plans-grid components that are no longer in use once this lands, but we can address them separately to keep this PR from growing indefinitely.

[noahtallen]

Tests well and couldn't find any other usage of the code.

[daledupreez]

@tyxla, I just merged a PR and was notified that ETK was modified, but when I went to deploy ETK, it looks like this PR hasn't been deployed yet. Could you take a look at D107274-code and maybe help me test?

I think my changes are effectively a no-op.

[noahtallen]

@daledupreez I took a look at that diff and it looks fine. I agree, it looks like a noop. (Mostly because we removed where that store was used in a separate PR/diff, so importing it there isn't really doing anything)

[tyxla]

I second this, it's a noop, we were just removing dead / unused code.