Refactored lef/right alighnment reset

blank-canvas-blocks/assets/ponyfill.css

@@ -109,12 +109,8 @@ img {
 	}
 }
 
-.wp-block-group:after {
-	clear: both;
-	content: ".";
-	display: block;
-	position: unset;
-	visibility: hidden;
+.wp-block-group {
+	overflow: auto;
 }
 
 ::selection {

blank-canvas-blocks/sass/base/_alignment.scss

@@ -16,10 +16,6 @@
 // When content is aligned left/right (particularly inside of a container) it is floated left/right
 // and needs something to ensure that the content follows the block rather than nestling up beside the floated element.  
 // The issue should be resolved upstream: https://github.com/WordPress/gutenberg/issues/10299
-.wp-block-group:after { 
-	clear: both;
-	content: ".";
-	display: block;
-	position: unset;
-	visibility: hidden;
+.wp-block-group { 
+	overflow: auto;
 }