SOLR-17742: handleSelect is now deprecated; log this

In 10; this is going to be removed (separate PR in progress)

Author: dsmiley

solr/core/src/java/org/apache/solr/core/SolrConfig.java

@@ -382,6 +382,9 @@ private SolrConfig(
       }
 
       handleSelect = get("requestDispatcher").boolAttr("handleSelect", false);
+      if (handleSelect) {
+        DeprecationLog.log("handleSelect", "handleSelect is deprecated");
+      }
       addHttpRequestToContext = requestParsersNode.boolAttr("addHttpRequestToContext", false);
       if (addHttpRequestToContext) {
         DeprecationLog.log("addHttpRequestToContext", "addHttpRequestToContext is deprecated");