* fixed #302 update Spring-Boot to Version to 2.3.7

* Issue #303 update Spring-Boot to Version to 2.4.1
* fixed #304 update webjars for bootstrap et al.
* fixed #305 Update spring-data-releasetrain to latest GA
* fixed #306 Update spring-session-bom to latest GA

Author: thomaswoehlke

src/main/resources/templates/layout/page.html

@@ -72,7 +72,7 @@
 	</footer>
 	<script th:src="@{/js/google-analytics.js}"></script>
     <script th:src="@{/webjars/jquery/3.5.1/jquery.js}"></script>
-    <script th:src="@{/webjars/popper.js/2.5.4/umd/popper.min.js}"></script>
+    <script th:src="@{/webjars/popper.js/1.16.1/umd/popper.min.js}"></script>
     <script th:src="@{/webjars/bootstrap/4.5.3/js/bootstrap.bundle.js}"></script>
     <script th:src="@{/webjars/font-awesome/5.15.1/js/all.js}"></script>
 	<!--/* Per-page placeholder for additional links */-->