Modularize the ingest-user-agent component (#87747)

modules/ingest-user-agent/src/main/java/module-info.java

@@ -0,0 +1,12 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+module org.elasticsearch.ingest.useragent {
+    requires org.elasticsearch.server;
+    requires org.elasticsearch.xcontent;
+}