Use updated attributes when saving tokenizers
# What does this PR do?

Use updated attributes when saving tokenizers.

Fix #20395
_The documentation is not available anymore as the PR was closed or merged._<|||||>For the record: running slow tests with the generic fix:

2 are (By-)T5 issues, other 3 from Bert/RocBert/NLLB

```bash
=FAILED tests/models/bert/test_tokenization_bert_tf.py::BertTokenizationTest::test_saved_model - ValueError: The two structures don't have the same nested structure.
FAILED tests/models/byt5/test_tokenization_byt5.py::ByT5TokenizationTest::test_added_token_serializable - ValueError: Both extra_ids (125) and additional_special_tokens (['new_token']) are provided to ByT5Tokenizer. In this case the additional_special_tokens must include the extra_ids tokens
FAILED tests/models/nllb/test_tokenization_nllb.py::NllbTokenizationTest::test_save_pretrained - ValueError: Non-consecutive added token 'ar_AR' found. Should have index 1229 but has index 1204 in saved vocabulary.
FAILED tests/models/roc_bert/test_tokenization_roc_bert.py::BertTokenizationTest::test_sequence_builders - assert [1, 5, 6, 2] == [101, 5, 6, 102]
FAILED tests/models/t5/test_tokenization_t5.py::T5TokenizationTest::test_added_token_serializable - ValueError: Both extra_ids (100) and additional_special_tokens (['new_token']) are provided to T5Tokenizer. In this case the additional_special_tokens must include the extra_ids tokens

```<|||||>Will try to make tokenization code better, but need to merge in order to unblock tiny model creation (so for pipeline testing and ONNX testing)