Fix similarity bwc tests for Knn vector builder (#94872)

Simple fencepost error 🤦 

closes https://github.com/elastic/elasticsearch/issues/94849

server/src/test/java/org/elasticsearch/search/vectors/AbstractKnnVectorQueryBuilderTestCase.java

@@ -226,12 +226,7 @@ abstract class AbstractKnnVectorQueryBuilderTestCase extends AbstractQueryTestCa
             query.numCands(),
             null
         ).queryName(query.queryName()).boost(query.boost()).addFilterQueries(query.filterQueries());
-        TransportVersion beforeSimilarity = TransportVersionUtils.randomVersionBetween(
-            random(),
-            TransportVersion.V_8_7_0,
-            TransportVersion.V_8_8_0
-        );
-        assertBWCSerialization(query, queryNoSimilarity, beforeSimilarity);
+        assertBWCSerialization(query, queryNoSimilarity, TransportVersion.V_8_7_0);
     }
 
     public void testBWCVersionSerializationByteQuery() throws IOException {

server/src/test/java/org/elasticsearch/search/vectors/KnnByteVectorQueryBuilderTests.java

@@ -8,10 +8,8 @@
 
 package org.elasticsearch.search.vectors;
 
-import org.apache.lucene.tests.util.LuceneTestCase;
 import org.elasticsearch.index.mapper.vectors.DenseVectorFieldMapper;
 
-@LuceneTestCase.AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/94849")
 public class KnnByteVectorQueryBuilderTests extends AbstractKnnVectorQueryBuilderTestCase {
     @Override
     DenseVectorFieldMapper.ElementType elementType() {

server/src/test/java/org/elasticsearch/search/vectors/KnnVectorQueryBuilderTests.java

@@ -8,10 +8,8 @@
 
 package org.elasticsearch.search.vectors;
 
-import org.apache.lucene.tests.util.LuceneTestCase;
 import org.elasticsearch.index.mapper.vectors.DenseVectorFieldMapper;
 
-@LuceneTestCase.AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/94849")
 public class KnnVectorQueryBuilderTests extends AbstractKnnVectorQueryBuilderTestCase {
     @Override
     DenseVectorFieldMapper.ElementType elementType() {