Update spearhead/assets/sass/_block-extends.scss

Co-authored-by: Jeff Ong <jeff.ong@automattic.com>

spearhead/assets/sass/_block-extends.scss

@@ -1,3 +1,2 @@
 // Import the block extends
-@import "block-extends/button";
-@import "block-extends/latest-posts";
+@import "block-extends/latest-posts";