Rewrite conditional class definition

src/components/molecules/Location.svelte

@@ -101,8 +101,9 @@
         <div class="location__photos">
             {#each location.photos as { image }, index}
                 {#if image}
+                    {@const classes = ['location__photo', index === photoIndex ? 'is-visible' : null].join(' ').trim()}
                     <Image
-                        class={`location__photo ${index === photoIndex ? 'is-visible' : ''}`}
+                        class={classes}
                         id={image.id}
                         sizeKey="photo-thumbnail"
                         width={340} height={226}