Fix variations and attributes layout when running WP >= 5.5

This commit fixes the layout of the sections of the product page in the admin that display variations and attributes. It was broken since WP 5.5 was releases. This version of WP removed a CSS rule that WooCommerce uses (see 22d0cd6c96 (diff-fc8970b78a0739bd367f17c3a8e552e6L1993)). So this commit simply adds this rule back.

See #27326

assets/css/admin.scss

@@ -5067,6 +5067,7 @@ img.help_tip {
 
 		.handlediv {
 			width: 27px;
+			float: right;
 
 			&::before {
 				content: "\f142" !important;