[xgb] Fix NDArray multiple read issue

[frankfliu]

Change-Id: Icb1d8e2906e63e22e1efecabe34853a9c2edefc6

Description

Brief description of what this PR is about

• If this change is a backward incompatible change, why must this change be made?
• Interesting edge cases to note here

[codecov-commenter]

Codecov Report

Merging #1239 (a756335) into master (8a76045) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##             master    #1239   +/-   ##
=========================================
  Coverage     70.22%   70.22%           
+ Complexity     5053     5052    -1     
=========================================
  Files           487      487           
  Lines         22217    22218    +1     
  Branches       2359     2359           
=========================================
+ Hits          15602    15603    +1     
+ Misses         5412     5410    -2     
- Partials       1203     1205    +2     

Impacted Files	Coverage Δ
...st/src/main/java/ai/djl/ml/xgboost/XgbNDArray.java	95.83% <100.00%> (+0.18%)	⬆️
...ava/ai/djl/translate/ServingTranslatorFactory.java	78.28% <0.00%> (-1.32%)	⬇️
.../main/java/ai/djl/benchmark/AbstractBenchmark.java	90.00% <0.00%> (-1.18%)	⬇️
...mark/src/main/java/ai/djl/benchmark/Arguments.java	88.42% <0.00%> (-0.53%)	⬇️
api/src/main/java/ai/djl/repository/Artifact.java	87.80% <0.00%> (+1.62%)	⬆️
api/src/main/java/ai/djl/inference/Predictor.java	91.34% <0.00%> (+2.88%)	⬆️

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