Change the current English links to Japanese links for JA docs

[lilin90]

In the translated TiDB docs in Japanese:

• For links using the standard relative path, the links are Japanese ones and work well.
• For absolute URLs using the entire the link address, the links remain English ones. Such links exist in:
  • The learning path on the main page of each active TiDB LTS version. For example, https://docs.pingcap.com/ja/tidb/stable
    
  • The links in HTML tables. For example, https://docs.pingcap.com/ja/tidbcloud/dev-guide-third-party-support#driver
    

[shhdgit]

Will support the ExternalLink in this pr:
pingcap/website-docs#569

We can use [TiDBセルフマネージドとは](/overview?target=_blank) instead of [TiDBセルフマネージドとは](https://docs.pingcap.com/tidb/v8.1/overview) for the relative path which needs to be opened in the new window.

example: #19741