A11y: Removed unnecessary application role from list of outcomes

Fixes CNVS-17749

Test plan:
- Create some outcomes.
- Navigate to the list of outcomes
- Validate that each item in the list is accessible via the keyboard
- Validate that each item is accessible via a screen reader.

Change-Id: I9f8feb1e43cc595cff4e96a3eaa562ecd4f9b522
Reviewed-on: https://gerrit.instructure.com/46526
Reviewed-by: Simon Williams <simon@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Adam Stone <astone@instructure.com>
Product-Review: Aaron Cannon <acannon@instructure.com>

Author: Aaron Cannon

app/views/jst/outcomes/browser.handlebars

@@ -28,7 +28,7 @@
   {{/unless}}
 
   <div class="outcomes-main border border-rbl">
-    <div class="outcomes-sidebar" role="application">
+    <div class="outcomes-sidebar">
       <div class="wrapper"></div>
     </div>
     <div class="outcomes-content">