[AINode] IoTDBTreeModelDataset bug fix

[CRZbulabula]

Fix a small bug that the tree model dataset does not convert the result into torch.tensor when first invoked

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 39.11%. Comparing base (65b18ff) to head (3fd4853).
Report is 4 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #15869      +/-   ##
============================================
+ Coverage     39.10%   39.11%   +0.01%     
  Complexity      198      198              
============================================
  Files          4845     4845              
  Lines        315627   315627              
  Branches      39644    39644              
============================================
+ Hits         123412   123451      +39     
+ Misses       192215   192176      -39     

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