Update xcontent field name

Author: thecoop

docs/changelog/121784.yaml

@@ -1,5 +1,5 @@
 pr: 121784
-summary: Add a lenient option to text similarity reranking
+summary: Optionally allow text similarity reranking to fail
 area: Search
 type: enhancement
-issues: []
+issues: [116796]

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/rank/textsimilarity/TextSimilarityRankRetrieverBuilder.java

@@ -44,7 +44,7 @@ public class TextSimilarityRankRetrieverBuilder extends CompoundRetrieverBuilder
     public static final ParseField INFERENCE_ID_FIELD = new ParseField("inference_id");
     public static final ParseField INFERENCE_TEXT_FIELD = new ParseField("inference_text");
     public static final ParseField FIELD_FIELD = new ParseField("field");
-    public static final ParseField FAILURES_ALLOWED_FIELD = new ParseField("failures_allowed");
+    public static final ParseField FAILURES_ALLOWED_FIELD = new ParseField("allow_rerank_failures");
 
     public static final ConstructingObjectParser<TextSimilarityRankRetrieverBuilder, RetrieverParserContext> PARSER =
         new ConstructingObjectParser<>(TextSimilarityRankBuilder.NAME, args -> {

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/rank/textsimilarity/TextSimilarityRankRetrieverBuilderTests.java

@@ -140,7 +140,7 @@ public void testTextSimilarityRetrieverParsing() throws IOException {
                   "inference_text": "my-inference-text",
                   "rank_window_size": 100,
                   "min_score": 20.0,
-                  "lenient": true,
+                  "allow_rerank_failures": true,
                   "_name": "foo_reranker"
                 }
               }