fix: remove duplicate (unclosed) tag (#35682)

This PR removes some bad (duplicated) markup in the static tab file. The current behavior leads to an unclosed HTML tag, which can be confirmed by viewing the document source.

lms/templates/courseware/static_tab.html

@@ -33,7 +33,6 @@ ${HTML(fragment.foot_html())}
       lang=${course.language}
     % endif
     >
-    <section class="container">
       <div class="static_tab_wrapper">
         ${HTML(fragment.body_html())}
       </div>