reduce z-index of homepage hero title to enable search click

opentech/static_src/src/sass/public/components/_wrapper.scss

@@ -232,7 +232,7 @@
 
         .header--homepage & {
             position: relative;
-            z-index: 9;
+            z-index: 8;
             align-items: flex-start;
             justify-content: center;
             height: 100%;