### Description

Dynamic mappings can greatly help the getting started experience but they currently don't apply to all types, one example is `dense_vector`.

It's been suggested to automatically map float arrays as dense vectors when there are more than 100 values, or a heuristic along these lines.
server/src/main/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapper.java
private final ElementType elementType;
        private final int dims;
        private final boolean indexed;
        private final VectorSimilarity similarity;
        private final IndexVersion indexVersionCreated;
        public DenseVectorFieldType(
            String name,
            IndexVersion indexVersionCreated,
            ElementType elementType,
            int dims,
            boolean indexed,
            VectorSimilarity similarity,
            Map<String, String> meta