Gutenberg: v19.9.x plugin upgrade

[gutenberg-plugin-upgrade-bot]

Previous upgrade: #96821
Release notes:

Install and activate

• Install and activate v19.9.0-rc.1 on edge (######-code)
• Install and activate v19.9.0 on edge (######-code)
• Activate v19.9.0 on production (######-code)
• Request v19.9.0 AT upgrade (######-p2)

Testing

• v19.9.0 Desktop viewport E2E
• v19.9.0 Mobile viewport E2E
• v19.9.0 WPCOM core (######-code)

Publish internal announcements

• Slack: #team-calypso
• Slack: #dotcom-happy-announce
• P2: wpcomhappy

Wrap-up

• Clean up unused releases
• Add log entry to the Gutenberg Upgrade Log (pcoGjb-g-p2)
• Open a new issue for the next upgrade, transfer remaining tasks, close this issue.

Blockers 🤷‍♀️

Other Issues 🐛

Issues transferred from previous release(s)

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cc @Automattic/gutenberg-upgrades