Remove unsupported pooling modes

Signed-off-by: Aivin V. Solatorio <avsolatorio@gmail.com>

1_Pooling/config.json

@@ -3,7 +3,5 @@
   "pooling_mode_cls_token": true,
   "pooling_mode_mean_tokens": false,
   "pooling_mode_max_tokens": false,
-  "pooling_mode_mean_sqrt_len_tokens": false,
-  "pooling_mode_weightedmean_tokens": false,
-  "pooling_mode_lasttoken": false
-}
+  "pooling_mode_mean_sqrt_len_tokens": false
+}