MDL-62465 assign: Allow grade scrolling

Remove the custom override that disables no-overflow in the grading table. This page is better to use
when the grading table is scrollable and the controls around it are not scrollable.

theme/boost/scss/moodle/modules.scss

@@ -522,9 +522,6 @@ div#dock {
 .path-mod-assign [data-region="grade-actions-panel"] [data-region="grade-actions"] .collapse-buttons {
     top: auto;
 }
-.path-mod-assign .no-overflow {
-    overflow: initial;
-}
 
 // This section removes the responsiveness from the form in the grading panel
 $popout-header-font-size: 1.5 * $font-size-base;

theme/boost/style/moodle.css

@@ -15767,9 +15767,6 @@ div#dock {
 .path-mod-assign [data-region="grade-actions-panel"] [data-region="grade-actions"] .collapse-buttons {
   top: auto; }
 
-.path-mod-assign .no-overflow {
-  overflow: initial; }
-
 .path-mod-assign #page-content [data-region="grade-panel"] .mform:not(.unresponsive) .fcontainer .fitem.popout .felement {
   height: calc(100% - 4rem); }