### 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/test/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapperTests.java
.startObject("index_options")
                    .field("type", "hnsw")
                    .field("m", 5)
                    .field("ef_construction", 80)
                    .endObject()
            )
        );
    }
    @Override
    protected boolean supportsStoredFields() {
        return false;
    }
    @Override
    protected boolean supportsIgnoreMalformed() {
        return false;
    }
    @Override
    protected void assertSearchable(MappedFieldType fieldType) {
        assertThat(fieldType, instanceOf(DenseVectorFieldType.class));
        assertEquals(fieldType.isIndexed(), indexed);
        assertEquals(fieldType.isSearchable(), indexed);
    }
    protected void assertExistsQuery(MappedFieldType fieldType, Query query, LuceneDocument fields) {
        assertThat(query, instanceOf(FieldExistsQuery.class));
        FieldExistsQuery existsQuery = (FieldExistsQuery) query;
        assertEquals("field", existsQuery.getField());
        assertNoFieldNamesField(fields);
    }