Blockbase: Remove alignment fix (#4186)

blockbase/assets/ponyfill.css

@@ -79,10 +79,6 @@ img {
 	}
 }
 
-.wp-block-group:not(.site-header) {
-	overflow: auto;
-}
-
 .aligncenter {
 	text-align: center;
 }

blockbase/sass/base/_alignment.scss

@@ -25,13 +25,6 @@
 	}
 }
 
-// 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:not(.site-header) {
-	overflow: auto;
-}
-
 // This was added for the 'site-logo' block which centers with an 'align:center' attribute
 // instead of 'textAlign' center which sets an .aligncenter class instead of a has-text-align-center
 // class which would do this for us.  I'm not sure why but this centers things appropriately.