feat(styles): sets default aspect ratio for iframe

Ensures a default aspect ratio of 1:1 for iframes that do not have an explicit aspect ratio defined.
This prevents layout issues where the iframe might collapse or render incorrectly, especially during initial loading or when aspect ratio is not properly handled by the embedding context.

Author: firestar300

src/blockparty-iframe/style.scss

@@ -11,4 +11,9 @@
 		width: 100%;
 		height: 100%;
 	}
+
+	&:not(.has-aspect-ratio) {
+		aspect-ratio: 1;
+		min-height: unset;
+	}
 }