Your requirements could not be resolved to an installable set of packages.
Problem 1
- orchestra/workbench dev-master requires orchestra/testbench-core ^7.28.0 || ^8.8.0 -> found orchestra/testbench-core[7.x-dev, 8.x-dev] but it conflicts with your root composer.json require (dev-workbench).
- orchestra/workbench 0.x-dev is an alias of orchestra/workbench dev-master and thus requires it to be installed too.
- Root composer.json requires orchestra/workbench 0.x-dev -> satisfiable by orchestra/workbench[0.x-dev (alias of dev-master)].