fix: Fix wrong event type of AntTreeNodeMouseEvent

[jirkalhotka]

🤔 This is a ...

• New feature
• Bug fix
• Site / document update
• Component style update
• TypeScript definition update
• Refactoring
• Code style optimization
• Test Case
• Branch merge
• Other (about what?)

🔗 Related issue link

#21102 fixed this in 4.x.x, now adding a fix for 3.x.x

💡 Background and solution

This fixes #16618 – the fix suggested in the issue which was implemented is wrong, the event type is actually a React.DragEvent

📝 Changelog

Language	Changelog
🇺🇸 English
🇨🇳 Chinese

☑️ Self Check before Merge

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

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[codecov]

Codecov Report

Merging #21200 into 3.x-stable will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           3.x-stable   #21200   +/-   ##
===========================================
  Coverage       97.82%   97.82%           
===========================================
  Files             286      286           
  Lines            7754     7754           
  Branches         2185     2188    +3     
===========================================
  Hits             7585     7585           
  Misses            169      169

Impacted Files	Coverage Δ
components/tree/Tree.tsx	96.66% <ø> (ø)	⬆️

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