Remove gaps under nav on build page

app/assets/stylesheets/framework/sidebar.scss

@@ -78,16 +78,16 @@
 
 .right-sidebar {
   border-left: 1px solid $border-color;
-  height: calc(100% - #{$header-height});
+  height: calc(100% - #{$new-navbar-height});
 
   &.affix {
     position: fixed;
-    top: $header-height;
+    top: $new-navbar-height;
   }
 }
 
 .with-performance-bar .right-sidebar.affix {
-  top: $header-height + $performance-bar-height;
+  top: $new-navbar-height + $performance-bar-height;
 }
 
 @mixin maintain-sidebar-dimensions {

app/assets/stylesheets/pages/builds.scss

@@ -64,10 +64,10 @@
     color: $gl-text-color;
     position: sticky;
     position: -webkit-sticky;
-    top: $header-height;
+    top: $new-navbar-height;
 
     &.affix {
-      top: $header-height;
+      top: $new-navbar-height;
     }
 
     // with sidebar
@@ -174,10 +174,10 @@
 
 .with-performance-bar .build-page {
   .top-bar {
-    top: $header-height + $performance-bar-height;
+    top: $new-navbar-height + $performance-bar-height;
 
     &.affix {
-      top: $header-height + $performance-bar-height;
+      top: $new-navbar-height + $performance-bar-height;
     }
   }
 }