Regenerate metadata and README with blocked treebank filtering

- metadata-2.17.json now includes "blocked" property for all treebanks
- README-2.17 filters out blocked treebanks (pt_cintil) from configs
- Blocked treebanks are identified via tools/blocked_treebanks.yaml

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tools/README-2.17

@@ -1704,14 +1704,6 @@ configs:
     path: parquet/pt_bosque/dev.parquet
   - split: test
     path: parquet/pt_bosque/test.parquet
-- config_name: pt_cintil
-  data_files:
-  - split: train
-    path: parquet/pt_cintil/train.parquet
-  - split: dev
-    path: parquet/pt_cintil/dev.parquet
-  - split: test
-    path: parquet/pt_cintil/test.parquet
 - config_name: pt_gsd
   data_files:
   - split: train