Update CSS preprocessors to v8.0.2

Author: renovate[bot]

package.json

@@ -108,7 +108,7 @@
         "@tryghost/theme-translations": "^0.0.9",
         "autoprefixer": "10.5.0",
         "beeper": "2.1.0",
-        "cssnano": "8.0.1",
+        "cssnano": "8.0.2",
         "gscan": "6.3.0",
         "gulp": "5.0.1",
         "gulp-concat": "2.6.1",