BREAKING CHANGE: Previously, when using setup-magento in extension mode, the magento 2 repo root was ../magento2 (outside of the extension folder). Due to interactions with `cache-magento` we need to keep magento inside the GITHUB_WORKSPACE (the root repo). We now do this in the `_ghamagento` folder. If you rely on the `steps.setup-magento.outputs.path` nothing changes for you. But, if you hardcoded the path, it's likely broken.