While running the composer can't install the css-tree-shaking due to symfony/css-selector. The following error is displaying.
-drupaljedi/css-tree-shaking 1.1.0 requires symfony/css-selector ^3 -> found symfony/css-selector[v3.0.0-BETA1, ..., 3.4.x-dev] but the package is fixed to v4.4.37 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.