Block Directory: Standardize reduced motion handling using media quer…

…ies (#68420)

Co-authored-by: im3dabasia <im3dabasia1@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>

packages/block-directory/src/components/downloadable-block-list-item/style.scss

@@ -15,7 +15,10 @@
 	background: none;
 	border: 0;
 	text-align: left;
-	transition: box-shadow 0.1s linear;
+
+	@media not (prefers-reduced-motion) {
+		transition: box-shadow 0.1s linear;
+	}
 
 	// The item contains absolutely positioned items.
 	// Set `position: relative` on the parent to prevent overflow issues