Disable dataset-viewer to keep old datasets<4.7 clients working

The datasets-server auto-generated schema uses the new Json() feature type (added in datasets==4.7.0) because some rows store cplr_opts/lead/meander as JSON strings and others as dicts. This causes datasets<4.7 clients (including the version pinned transitively by SQuADDS==0.4.3 via 'datasets>=2.19') to crash with: ValueError: Feature type 'Json' not found. Setting viewer: false suppresses the /info endpoint's exported_dataset_infos so datasets clients fall through to per-file schema inference and work across all supported versions. The data files themselves are unchanged.

README.md

@@ -1,5 +1,6 @@
 ---
 license: mit
+viewer: false
 configs:
 - config_name: qubit-TransmonCross-cap_matrix
   data_files: