Remove long deprecated special 'base' case for similarity service (#118115)

Author: benwtrent

server/src/main/java/org/elasticsearch/index/similarity/SimilarityService.java

@@ -20,8 +20,6 @@
 import org.apache.lucene.search.similarities.Similarity.SimScorer;
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.TriFunction;
-import org.elasticsearch.common.logging.DeprecationCategory;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.Maps;
 import org.elasticsearch.core.Nullable;
@@ -40,7 +38,6 @@
 import java.util.function.Supplier;
 
 public final class SimilarityService {
-    private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(SimilarityService.class);
     public static final String DEFAULT_SIMILARITY = "BM25";
     private static final Map<String, Function<IndexVersion, Supplier<Similarity>>> DEFAULTS;
     public static final Map<String, TriFunction<Settings, IndexVersion, ScriptService, Similarity>> BUILT_IN;
@@ -115,13 +112,6 @@ public SimilarityService(
         defaultSimilarity = (providers.get("default") != null)
             ? providers.get("default").get()
             : providers.get(SimilarityService.DEFAULT_SIMILARITY).get();
-        if (providers.get("base") != null) {
-            deprecationLogger.warn(
-                DeprecationCategory.QUERIES,
-                "base_similarity_ignored",
-                "The [base] similarity is ignored since query normalization and coords have been removed"
-            );
-        }
     }
 
     /**