[tokenizer] fix ChineseBertTokenizer with max_length/max_seq_len

[SevenSamon]

PR types

Bug fixes｜修改ChineseBertTokenizer不存在Max_length参数问题，以及pypinyin的import方式修改

PR changes

Models｜paddlenlp/transformers/chinesebert/tokenizer.py

Description

修改ChineseBertTokenizer不存在Max_length参数问题，以及pypinyin的import方式修改

[paddle-bot]

Thanks for your contribution!

[codecov]

Codecov Report

❌ Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 55.00%. Comparing base (ecfe0ac) to head (6915194).
⚠️ Report is 960 commits behind head on develop.

⚠️ Current head 6915194 differs from pull request most recent head 4c265bb

Please upload reports for the commit 4c265bb to get more accurate results.

Files with missing lines	Patch %	Lines
paddlenlp/transformers/chinesebert/tokenizer.py	0.00%	4 Missing ⚠️

❌ Your patch status has failed because the patch coverage (0.00%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.
❌ Your project status has failed because the head coverage (55.00%) is below the target coverage (58.00%). You can increase the head coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8926      +/-   ##
===========================================
- Coverage    55.01%   55.00%   -0.02%     
===========================================
  Files          646      646              
  Lines       102242   102030     -212     
===========================================
- Hits         56252    56124     -128     
+ Misses       45990    45906      -84     

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[github-actions]

This Pull Request is stale because it has been open for 60 days with no activity. 当前Pull Request 60天内无活动，被标记为stale。

[github-actions]

This Pull Request is stale because it has been open for 60 days with no activity. 当前Pull Request 60天内无活动，被标记为stale。

[paddle-bot]

Automatically closed by Paddle-bot.