Run yarn install, or just yarn.
The lock file is updated in its entirety on any change to dependencies, i.e. when you run a yarn command.
From the Yarn docs:
Your yarn.lock file is auto-generated and should be handled entirely by Yarn. As you add/upgrade/remove dependencies with the Yarn CLI, it will automatically update your yarn.lock file. Do not edit this file directly as it is easy to break something.
(Emphasis my own)