Lucene 9.8 updates the vector dimension limit overridability. Moving it to the codec. 

We should switch our override to do this correctly now, instead of returning a `FieldType` overriding the value.

For now, this commit would belong in the `lucene_snapshot` branch.
server/src/test/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapperTests.java
private final int dims = between(5, 1000);
        private final ElementType elementType = randomFrom(ElementType.BYTE, ElementType.FLOAT);
        private final boolean indexed = randomBoolean();
        private final boolean indexOptionsSet = indexed && randomBoolean();
        @Override
        public SyntheticSourceExample example(int maxValues) throws IOException {
            Object value = elementType == ElementType.BYTE
                ? randomList(dims, dims, ESTestCase::randomByte)