SOLR-17956 Deprecate the XLSXResponseWriter in v9.10 (branch_9x) (#3775)

Backported from main branch dead9b6

Author: janhoy

solr/CHANGES.txt

@@ -62,6 +62,8 @@ Other Changes
 
 * SOLR-17952: Stream decorator test refactoring - use underscore rather than dot in aliases (Andy Webb)
 
+* SOLR-17956: XLSXResponseWriter has been deprecated and will be removed in a future release. (Jan Høydahl)
+
 ==================  9.9.1 ==================
 Bug Fixes
 ---------------------

solr/modules/extraction/src/java/org/apache/solr/handler/extraction/XLSXResponseWriter.java

@@ -48,6 +48,12 @@
 import org.apache.solr.schema.StrField;
 import org.apache.solr.search.ReturnFields;
 
+/**
+ * A .XLSX spreadsheet format {@link org.apache.solr.response.QueryResponseWriter}.
+ *
+ * @deprecated This class will be removed in a future release.
+ */
+@Deprecated(since = "9.10", forRemoval = true)
 public class XLSXResponseWriter extends RawResponseWriter {
 
   @Override

solr/modules/extraction/src/test/org/apache/solr/handler/extraction/TestXLSXResponseWriter.java

@@ -40,6 +40,7 @@
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+@SuppressWarnings("removal")
 public class TestXLSXResponseWriter extends SolrTestCaseJ4 {
 
   private static XLSXResponseWriter writerXlsx;

solr/solr-ref-guide/modules/query-guide/pages/response-writers.adoc

@@ -480,3 +480,8 @@ cp modules/extraction/lib/*.jar server/solr-webapp/webapp/WEB-INF/lib/
 ----
 
 Once the libraries are in place, you can add `wt=xlsx` to your request, and results will be returned as an XLSX sheet.
+
+[IMPORTANT]
+====
+The `XLSXResponseWriter` is deprecated and will be removed in a future release.
+====

solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-9.adoc

@@ -86,6 +86,10 @@ SolrJ users not using SolrClients that use Jetty HttpClient can safely exclude t
 
 Java has removed support for the Security Manager starting with Java 24; therefore, Solr will disable this feature when run with Java 24 or later. Solr previously used the Security Manager to provide an additional layer of protection against unintended file system access, network access, and process execution. Users upgrading to Java 24 or later should review their security practices and consider alternative measures, such as running Solr in containers or implementing additional operating system-level controls.
 
+=== Deprecations
+
+The `XLSXResponseWriter` is now deprecated.
+
 == Solr 9.9
 
 === SolrJ