How to disable show composer.json in domain's application list?
WordPress is installed on a domain. WordPress plugin with PHP dependencies that manage by Composer is installed on WordPress instance.
Observing composer.json items in the application list is an expected behavior. This feature was implemented to have a way to manage PHP dependencies with Composer from GUI.
Currently, the only way not to see such applications in the total list is to remove relevant "composer.json" files. Considering, that composers automatically updates libraries for installed WordPress plugins, deleting of them could cause unstable work of affected plugins.
More information about managing PHP Project dependencies with composer, including from GUI, is available in our documentation.