fix test

Author: markjhoy

server/src/test/java/org/elasticsearch/index/mapper/vectors/SparseVectorFieldMapperTests.java

@@ -150,7 +150,8 @@ public void testDefaults() throws Exception {
 
     public void testWithIndexOptionsPrune() throws Exception {
         DocumentMapper mapper = createDocumentMapper(fieldMapping(this::mappingWithIndexOptionsPrune));
-        assertEquals(Strings.toString(fieldMapping(this::mappingWithIndexOptionsPrune)), mapper.mappingSource().toString());
+        String expectedMapping = "{\"_doc\":{\"properties\":{\"field\":{\"type\":\"sparse_vector\",\"index_options\":{\"prune\":true,\"pruning_config\":{\"tokens_freq_ratio_threshold\":5.0,\"tokens_weight_threshold\":0.4}}}}}}"
+        assertEquals(expectedMapping, mapper.mappingSource().toString());
 
         ParsedDocument doc1 = mapper.parse(source(this::writeField));