fix: fixed active state border issue for add a new post button (#784)

Author: sundasnoreen12

src/discussions/posts/post-actions-bar/PostActionsBar.jsx

@@ -55,7 +55,7 @@ const PostActionsBar = () => {
           <Button
             variant={enableInContextSidebar ? 'plain' : 'brand'}
             className={classNames(
-              'my-0 font-style border-0 line-height-24',
+              'my-0 font-style line-height-24',
               { 'px-3 py-10px border-0': enableInContextSidebar },
             )}
             onClick={handleAddPost}