remove content-visibility css prop to avoid jumpy scrollbar (#10503)

packages/notebook/style/base.css

@@ -142,14 +142,6 @@
   background-color: var(--jp-cell-editor-active-background);
 }
 
-/*-----------------------------------------------------------------------------
-| Notebook cell
-|----------------------------------------------------------------------------*/
-
-.jp-Notebook-cell {
-  content-visibility: auto;
-}
-
 /*-----------------------------------------------------------------------------
 | Notebook drag and drop
 |----------------------------------------------------------------------------*/