From docs.grails.org/7.0.0-M1/guide/plugins.html#creatingAndInstallingPlugins:

In Grails 3.0 you should consider whether the plugin you create requires a web environment or whether the plugin can be used with other profiles. If your plugin does not require a web environment then use the "plugin" profile instead of the default "web-plugin" profile:

grails create-plugin <<PLUGIN NAME>> --profile=plugin

The docs shouldn't call out "In Grails 3.0..." and the sample command shown does not work.