feat: preserve gifs ratio, better for mobile

Author: peterpeterparker

webcomponents/core/src/components/extra/deckdeckgo-gif/deckdeckgo-gif.scss

@@ -36,7 +36,6 @@ div.deckgo-gif {
     height: var(--slide-height);
 
     --width: var(--slide-width);
-    --height: var(--slide-height);
 
     overflow: hidden;