fix(package): update postcss-image-set-polyfill to version 0.4.3 (#29)

Closes #28

Author: jescalan

package.json

@@ -24,7 +24,7 @@
     "postcss-custom-selectors": "^4.0.1",
     "postcss-font-family-system-ui": "^2.0.1",
     "postcss-font-variant": "^3.0.0",
-    "postcss-image-set-polyfill": "^0.3.5",
+    "postcss-image-set-polyfill": "^0.4.3",
     "postcss-import": "^10.0.0",
     "postcss-media-minmax": "^3.0.0",
     "postcss-nesting": "^4.0.1",