Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires wp-coding-standards/wpcs dev-master, found wp-coding-standards/wpcs[dev-feature/new-multi-line-comment-formatting-sniffs, ..., dev-3.0/classes-class-instantiation-phpcsutils-implementation, 0.3.0, ..., 0.14.1, 1.0.0, 1.1.0, 1.2.0, 1.2.1, 2.0.0-RC1, ..., 2.3.0, 3.0.0] but it does not match the constraint. Perhaps dev-master was renamed to dev-main?