Updating selectors for diff line

app/assets/javascripts/diffs/components/inline_diff_table_row.vue

@@ -102,7 +102,7 @@ export default {
       :line-type="newLineType"
       :is-bottom="isBottom"
       :is-hover="isHover"
-      class="diff-line-num new_line"
+      class="diff-line-num new_line qa-new-diff-line"
     />
     <td
       :class="line.type"

app/assets/javascripts/diffs/components/parallel_diff_table_row.vue

@@ -143,7 +143,7 @@ export default {
         :show-comment-button="true"
         :diff-view-type="parallelDiffViewType"
         line-position="right"
-        class="diff-line-num new_line qa-new-diff-line"
+        class="diff-line-num new_line"
       />
       <td
         :id="line.right.lineCode"