Merge branch '34153-extend-mr-tabs' into 'master'

Extend MR tabs a bit to cover up the avatar holder and collapse icon on scroll

Closes #34153

See merge request !12589

app/assets/stylesheets/pages/merge_requests.scss

@@ -731,11 +731,11 @@
 
 .merge-request-tabs-holder {
   top: $header-height;
-  z-index: 100;
+  z-index: 200;
   background-color: $white-light;
   border-bottom: 1px solid $border-color;
 
-  @media(min-width: $screen-sm-min) {
+  @media (min-width: $screen-sm-min) {
     position: sticky;
     position: -webkit-sticky;
   }
@@ -770,6 +770,12 @@
     max-width: $limited-layout-width;
     margin-left: auto;
     margin-right: auto;
+
+    .inner-page-scroll-tabs {
+      background-color: $white-light;
+      margin-left: -$gl-padding;
+      padding-left: $gl-padding;
+    }
   }
 }