chore: bump version to 6.0.21

[yixinshark]

bump version to 6.0.21

Log: bump version to 6.0.21

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: yixinshark

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• debian/deepin/OWNERS

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[deepin-ci-robot]

deepin pr auto review

关键摘要:

• 检查是否有必要更新版本号，如果更新没有实际功能变化，则不需要更新版本号。
• 确认是否有更新日志描述了这次版本更新的具体内容。
• 检查是否有其他相关的提交或更改影响了这个包，确保它们已经被合并。

是否建议立即修改:

• 是，如果更新日志不充分或者版本号没有必要更新，应该立即进行修正。

[yixinshark]

/integr-topic dde-session-ui-21

[deepin-ci-robot]

Integrate topic: dde-session-ui-21 failed: topic[dde-session-ui-21]'s projectV2 not found

[yixinshark]

/topic dde-session-ui-21

[github-actions[bot]]

TAG Bot

TAG: 6.0.21 EXISTED: no DISTRIBUTION: unstable

[deepin-ci-robot]

Add topic: dde-session-ui-21 successed.

[yixinshark]

/integr-topic dde-session-ui-21

[deepin-ci-robot]

Integrated with pr https://github.com/deepin-community/Repository-Integration/pull/1835

[yixinshark]

/forcemerge

[deepin-bot[bot]]

This pr force merged! (status: blocked)