[Docs] fix typos in some tokenizer docs (#22256)

[Docs] fix typos
Co-authored-by: yesinkim <yesinkim@yesinkimui-MacBookAir.local>

src/transformers/models/longformer/tokenization_longformer.py

@@ -124,7 +124,7 @@ class LongformerTokenizer(PreTrainedTokenizer):
     >>> from transformers import LongformerTokenizer
     >>> tokenizer = LongformerTokenizer.from_pretrained("allenai/longformer-base-4096")
     >>> tokenizer("Hello world")['input_ids']
-    [0, 31414, 232, 328, 2]
+    [0, 31414, 232, 2]
     >>> tokenizer(" Hello world")['input_ids']
     [0, 20920, 232, 2]
     ```

src/transformers/models/longformer/tokenization_longformer_fast.py

@@ -100,7 +100,7 @@ class LongformerTokenizerFast(PreTrainedTokenizerFast):
     >>> from transformers import LongformerTokenizerFast
     >>> tokenizer = LongformerTokenizerFast.from_pretrained("allenai/longformer-base-4096")
     >>> tokenizer("Hello world")['input_ids']
-    [0, 31414, 232, 328, 2]
+    [0, 31414, 232, 2]
     >>> tokenizer(" Hello world")['input_ids']
     [0, 20920, 232, 2]
     ```

src/transformers/models/roberta/tokenization_roberta.py

@@ -115,7 +115,7 @@ class RobertaTokenizer(PreTrainedTokenizer):
     >>> from transformers import RobertaTokenizer
     >>> tokenizer = RobertaTokenizer.from_pretrained("roberta-base")
     >>> tokenizer("Hello world")['input_ids']
-    [0, 31414, 232, 328, 2]
+    [0, 31414, 232, 2]
     >>> tokenizer(" Hello world")['input_ids']
     [0, 20920, 232, 2]
     ```

src/transformers/models/roberta/tokenization_roberta_fast.py

@@ -85,7 +85,7 @@ class RobertaTokenizerFast(PreTrainedTokenizerFast):
     >>> from transformers import RobertaTokenizerFast
     >>> tokenizer = RobertaTokenizerFast.from_pretrained("roberta-base")
     >>> tokenizer("Hello world")['input_ids']
-    [0, 31414, 232, 328, 2]
+    [0, 31414, 232, 2]
     >>> tokenizer(" Hello world")['input_ids']
     [0, 20920, 232, 2]
     ```