Index: wp-includes/css/dist/block-library/style-rtl.css
===================================================================
--- wp-includes/css/dist/block-library/style-rtl.css	(revision 46791)
+++ wp-includes/css/dist/block-library/style-rtl.css	(working copy)
@@ -701,7 +701,7 @@
               mask-size: contain;
       -webkit-mask-position: center;
               mask-position: center;
-      border-radius: none; } }
+      border-radius: 0; } }
 
 .wp-block-latest-comments__comment {
   font-size: 15px;
Index: wp-includes/css/dist/block-library/style.css
===================================================================
--- wp-includes/css/dist/block-library/style.css	(revision 46791)
+++ wp-includes/css/dist/block-library/style.css	(working copy)
@@ -709,7 +709,7 @@
               mask-size: contain;
       -webkit-mask-position: center;
               mask-position: center;
-      border-radius: none; } }
+      border-radius: 0; } }
 
 .wp-block-latest-comments__comment {
   font-size: 15px;