Fix the masked LM model

src/transformers/models/tapas/modeling_tapas.py

@@ -925,6 +925,9 @@ class TapasForMaskedLM(TapasPreTrainedModel):
     def get_output_embeddings(self):
         return self.lm_head
 
+    def set_output_embeddings(self, word_embeddings):
+        self.lm_head = word_embeddings
+
     @add_start_docstrings_to_model_forward(TAPAS_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
     @replace_return_docstrings(output_type=MaskedLMOutput, config_class=_CONFIG_FOR_DOC)
     def forward(