chore(deps): update dependency postcss-preset-env to ~9.6.0

Author: renovate[bot]

package.json

@@ -86,7 +86,7 @@
     "gulp-sourcemaps": "~3.0.0",
     "gulp-terser": "~2.1.0",
     "postcss": "~8.4.35",
-    "postcss-preset-env": "~9.4.0",
+    "postcss-preset-env": "~9.6.0",
     "stylelint": "~15.11.0",
     "stylelint-config-standard-scss": "~11.1.0"
   },