The job was canceled because "_8_4__12_0__4_0_highest" failed.

Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires pimcore/pimcore ^12.0, found pimcore/pimcore[12.x-dev] but it does not match your minimum-stability. Problem 2 - Root composer.json requires pimcore/admin-ui-classic-bundle ^1.2 || ^2.0 -> satisfiable by pimcore/admin-ui-classic-bundle[v1.2, ..., v1.7.3]. - pimcore/admin-ui-classic-bundle[v1.2, ..., v1.3.0] require pimcore/pimcore ^11.1 -> found pimcore/pimcore[v11.1.0, ..., v11.5.2] but it conflicts with your root composer.json require (^12.0). - pimcore/admin-ui-classic-bundle v1.3.1 requires pimcore/pimcore ^11.1.3 -> found pimcore/pimcore[v11.1.3, ..., v11.5.2] but it conflicts with your root composer.json require (^12.0). - pimcore/admin-ui-classic-bundle[v1.3.2, ..., v1.3.5] require pimcore/pimcore ^11.1.4 -> found pimcore/pimcore[v11.1.4, ..., v11.5.2] but it conflicts with your root composer.json require (^12.0). - pimcore/admin-ui-classic-bundle[1.4.0, ..., v1.4.4] require pimcore/pimcore ^11.2.0 -> found pimcore/pimcore[v11.2.0, ..., v11.5.2] but it conflicts with your root composer.json require (^12.0). - pimcore/admin-ui-classic-bundle v1.4.5 requires pimcore/pimcore ~11.2.0 -> found pimcore/pimcore[v11.2.0, ..., v11.2.7] but it conflicts with your root composer.json require (^12.0). - pimcore/admin-ui-classic-bundle[v1.5.0, ..., v1.5.2] require pimcore/pimcore ~11.3.0 -> found pimcore/pimcore[v11.3.0, v11.3.1, v11.3.2, v11.3.3] but it conflicts with your root composer.json require (^12.0). - pimcore/admin-ui-classic-bundle[v1.5.3, ..., v1.5.5] require pimcore/pimcore ~11.3.1 -> found pimcore/pimcore[v11.3.1, v11.3.2, v11.3.3] but it conflicts with your root composer.json require (^12.0). - pimcore/admin-ui-classic-bundle[v1.6.0, ..., v1.6.6] require pimcore/pimcore ^11.3.1 -> found pimcore/pimcore[v11.3.1, ..., v11.5.2] but it conflicts with your root composer.json require (^12.0). - pimcore/admin-ui-classic-bundle[v1.7.0, ..., v1.7.3] require pimcore/pimcore ^11.5.0 -> found pimcore/pimcore[v11.5.0, v11.5.1, v11.5.2] but it conflicts with your root composer.json require (^12.0).