### CI Link

- https://gradle-enterprise.elastic.co/s/tl3jqzmzqyktq (PR branch)
- https://gradle-enterprise.elastic.co/s/6ao6q7f42tsly (main)

### Repro line

./gradlew ':server:test' --tests "org.elasticsearch.index.mapper.vectors.DenseVectorFieldMapperTests.testVectorSimilarity" -Dtests.seed=39343A357A78EC3 -Dtests.locale=zh-CN -Dtests.timezone=Africa/Maseru -Druntime.java=21

### Does it reproduce?

Yes

### Applicable branches

main

### Failure history

_No response_

### Failure excerpt

  2> java.lang.AssertionError: expected:<COSINE> but was:<DOT_PRODUCT>
        at __randomizedtesting.SeedInfo.seed([39343A357A78EC3:75EC84B47EC59CF]:0)
        at org.junit.Assert.fail(Assert.java:88)
        at org.junit.Assert.failNotEquals(Assert.java:834)
        at org.junit.Assert.assertEquals(Assert.java:118)
        at org.junit.Assert.assertEquals(Assert.java:144)
        at org.elasticsearch.index.mapper.vectors.DenseVectorFieldMapperTests.testVectorSimilarity(DenseVectorFieldMapperTests.java:776)
server/src/test/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapperTests.java
: randomList(dims, dims, ESTestCase::randomFloat);
            return new SyntheticSourceExample(value, value, this::mapping);
        }
        private void mapping(XContentBuilder b) throws IOException {
            b.field("type", "dense_vector");
            b.field("dims", dims);
            if (elementType == ElementType.BYTE || randomBoolean()) {
                b.field("element_type", elementType.toString());
            }
            if (indexed) {
                b.field("index", true);
                b.field("similarity", "l2_norm");
                if (indexOptionsSet) {
                    b.startObject("index_options");
                    b.field("type", "hnsw");
                    b.field("m", 5);
                    b.field("ef_construction", 50);
                    b.endObject();
                }
            } else {
                b.field("index", false);
            }
        }
        @Override
        public List<SyntheticSourceInvalidExample> invalidExample() {
            return List.of();
        }
    }
}