Remove outdated search JS

scipost_django/scipost/static/scipost/search-header.js

-function searchHeader() {
-    document.getElementById("header-search-button").addEventListener("click", function(event){
-        if (document.documentElement.clientWidth > 768) {
-            event.preventDefault();
-            var x = document.getElementById("header-search-form");
-            if (x.style.display === "none") {
-                x.style.display = "block";
-            } else {
-                x.style.display = "none";
-            }
-        }
-    });
-
-    document.getElementById("header-search-close-btn").addEventListener("click", function(event){
-        var x = document.getElementById("header-search-form");
-        x.style.display = "none";
-    });
-
-    if (document.documentElement.clientWidth <= 768) {
-        // Force-close if form is prefilled.
-        var x = document.getElementById("header-search-form");
-        x.style.display = "none";
-    }
-}
-searchHeader();