adopters: remove Pinterest (#6501)

[ti-chi-bot]

This is an automated cherry-pick of #6501

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• master (the latest development version)
• v5.2 (TiDB 5.2 versions)
• v5.1 (TiDB 5.1 versions)
• v5.0 (TiDB 5.0 versions)
• v4.0 (TiDB 4.0 versions)
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• v3.0 (TiDB 3.0 versions)
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• Delete files
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[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• CaitinChen

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[CaitinChen]

/merge

[ti-chi-bot]

@CaitinChen: /merge in this pull request requires 1 approval(s).

In response to this:

/merge

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[CaitinChen]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: fe66d33