remove unused node feature

Author: markjhoy

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/mapper/SemanticTextFieldMapper.java

@@ -143,9 +143,6 @@ public class SemanticTextFieldMapper extends FieldMapper implements InferenceFie
     public static final NodeFeature SEMANTIC_TEXT_INDEX_OPTIONS_WITH_DEFAULTS = new NodeFeature(
         "semantic_text.index_options_with_defaults"
     );
-    public static final NodeFeature SEMANTIC_TEXT_SPARSE_VECTOR_INDEX_OPTIONS_SUPPORT = new NodeFeature(
-        "semantic_text.sparse_vector_index_options_support"
-    );
 
     public static final String CONTENT_TYPE = "semantic_text";
     public static final String DEFAULT_ELSER_2_INFERENCE_ID = DEFAULT_ELSER_ID;