Remove external Javadoc links to Tiles and Ehcache

Support code for Apache Tiles and Ehcache has already been removed from
Spring Framework 6.0.

This commit therefore removes the configuration for external links to
these projects.

build.gradle

@@ -336,10 +336,7 @@ configure([rootProject] + javaProjects) { project ->
 			"https://www.ibm.com/docs/api/v1/content/SSEQTP_8.5.5/com.ibm.websphere.javadoc.doc/web/apidocs/",
 			"https://docs.jboss.org/jbossas/javadoc/4.0.5/connector/",
 			"https://docs.jboss.org/jbossas/javadoc/7.1.2.Final/",
-			"https://tiles.apache.org/tiles-request/apidocs/",
-			"https://tiles.apache.org/framework/apidocs/",
 			"https://www.eclipse.org/aspectj/doc/released/aspectj5rt-api/",
-			"https://www.ehcache.org/apidocs/2.10.4/",
 			"https://www.quartz-scheduler.org/api/2.3.0/",
 			"https://fasterxml.github.io/jackson-core/javadoc/2.10/",
 			"https://fasterxml.github.io/jackson-databind/javadoc/2.10/",