Upgrade cssnano from v4.1.10 to v4.1.11 (#8759)
Upgrade cssnano from v4.1.10 to v4.1.11 (#8759)

Removes the is-svg dependency since cssnano no longer depends on it.

Signed-off-by: Andy Pickering <d0291d42984e3fec2e88641a9237e7b823b02c58@redhat.com>
keegancsmith/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,prometheus/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,prometheus/prometheus,alileza/prometheus,alileza/prometheus