When the `lock` option is set to false, composer will not write a
`composer.lock` file to disk. This signals that the package is meant
to be developed with unlocked and always updated dependencies. At the
moment, both `install` and `update` are allowed to install the
dependencies for such a package. If #6822 is implemented, only `update`
should be used for packages without a lockfile.
https://github.com/composer/composer/issues/8354