removed MLM head for API use with feature extraction

config.json

@@ -1,6 +1,6 @@
 {
   "architectures": [
-    "BertForMaskedLM"
+    "BertModel"
   ],
   "attention_probs_dropout_prob": 0.1,
   "classifier_dropout": null,
@@ -20,5 +20,8 @@
   "transformers_version": "4.41.2",
   "type_vocab_size": 2,
   "use_cache": true,
-  "vocab_size": 30522
+  "vocab_size": 30522,
+  "task_specific_params": {
+    "feature-extraction": {}
+  }
 }