fix: mindmap demo duplicate node id, close #3256

[lloydzhou]

Description

Motivation and Context

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Enhancement (changes that improvement of current feature or performance)
• Refactoring (changes that neither fixes a bug nor adds a feature)
• Test Case (changes that add missing tests or correct existing tests)
• Code style optimization (changes that do not affect the meaning of the code)
• Docs (changes that only update documentation)
• Chore (changes that don't modify src or test files)

Self Check before Merge

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[lloydzhou]

修复后按照按照 #3256 操作后会渲染出label重复的两个节点（其中第二个节点的id已经被修改过了，不至于重复）

[x6-bot]

🎉 This PR is included in the following release 🎉

• @antv/x6-common@2.0.8
  • npm package (@latest dist-tag)
  • GitHub release

Thanks for being a part of the AntV community! 💪💯

[x6-bot]

🎉 This PR is included in the following release 🎉

• @antv/x6-common@2.0.10
  • npm package (@latest dist-tag)
  • GitHub release
• @antv/x6-plugin-transform@2.1.6
  • npm package (@latest dist-tag)
  • GitHub release

Thanks for being a part of the AntV community! 💪💯