Bump to bootstrap@5.3.0-alpha3 and only load it once

When loaded twice dropdown menus don't work.

Change-Id: I07e6b69c586ba499905627deafadc426d009e072
diff --git a/templates/header.htm b/templates/header.htm
index a4c5fb6..ec1372d 100644
--- a/templates/header.htm
+++ b/templates/header.htm
@@ -5,15 +5,14 @@
     <!-- Required meta tags -->
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
-    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-GLhlTQ8iRABdZLl6O3oVMWSktQOp6b7In1Zl3/Jr59b6EGGoI1aFkw7cmDA6j6gD" crossorigin="anonymous">
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-KK94CHFLLe+nY2dmCWGMq91rCGa5gtU4mk92HdvYe+M/SXH301p5ILy+dN9+nJOZ" crossorigin="anonymous">
     <title>Sign up for
         <?php echo $SERVICE_ACRONYM; ?>
     </title>
     <link href="//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap-glyphicons.css" rel="stylesheet">
     <link rel="stylesheet" href="<?php echo $BASE_URL?>/static/main.css">
     <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.3/jquery.min.js" integrity="sha512-STof4xm1wgkfm7heWqFJVn58Hm3EtS31XFaagaa8VMReCXAkQnJZ+jEy8PCC/iT18dFy95WcExNHFTqLyp72eQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
-    <script src="https://cdn.jsdelivr.net/npm/@popperjs/core@2.11.6/dist/umd/popper.min.js" integrity="sha384-oBqDVmMz9ATKxIep9tiCxS/Z9fNfEXiDAYTujMAeBAsjFuCZSmKbSSUnQlmh/jp3" crossorigin="anonymous"></script>
-    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/js/bootstrap.min.js" integrity="sha384-mQ93GR66B00ZXjt0YO5KlohRA5SY2XofN4zfuZxLkoj1gXtW8ANNCe9d5Y3eG5eD" crossorigin="anonymous"></script>
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha3/dist/js/bootstrap.bundle.min.js" integrity="sha384-ENjdO4Dr2bkBIFxQpeoTz1HIcje39Wm4jDKdf19U8gI4ddQ3GYNS7NTKfAdVQSZe" crossorigin="anonymous"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/4.1.1/core.min.js" integrity="sha512-t8vdA86yKUE154D1VlNn78JbDkjv3HxdK/0MJDMBUXUjshuzRgET0ERp/0MAgYS+8YD9YmFwnz6+FWLz1gRZaw==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/4.1.1/enc-hex.min.js" integrity="sha512-jDU0YCduSP8z0cvjfPFm7/zN/viOcmNWlq0GUIcjVhuv4WoKcMppghamg4aeuBtJaA0wjtYfxwQjPpVuYGEsBA==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/4.1.1/sha1.min.js" integrity="sha512-NHw1e1pc4RtmcynK88fHt8lpuetTUC0frnLBH6OrjmKGNnwY4nAnNBMjez4DRr9G1b+NtufOXLsF+apmkRCEIw==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>