Revert "fsmt slow test uses lists (huggingface#8031)"

This reverts commit b79010f.

tests/test_tokenization_fsmt.py

@@ -144,11 +144,11 @@ def test_match_encode_decode(self):
         # for src_text, _ in targets: print(f"""[\n"{src_text}",\n {model.encode(src_text).tolist()}\n],""")
 
         for src_text, tgt_input_ids in targets:
-            encoded_ids = tokenizer_enc.encode(src_text, return_tensors=None)
-            self.assertListEqual(encoded_ids, tgt_input_ids)
+            input_ids = tokenizer_enc.encode(src_text, return_tensors="pt")[0].tolist()
+            self.assertListEqual(input_ids, tgt_input_ids)
 
             # and decode backward, using the reversed languages model
-            decoded_text = tokenizer_dec.decode(encoded_ids, skip_special_tokens=True)
+            decoded_text = tokenizer_dec.decode(input_ids, skip_special_tokens=True)
             self.assertEqual(decoded_text, src_text)
 
     @unittest.skip("FSMTConfig.__init__  requires non-optional args")