feat: replace JUnit with TestNG

[Copilot]

fix: #506

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 68.05%. Comparing base (aa90a03) to head (65f4d65).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #507      +/-   ##
==========================================
- Coverage   68.08%   68.05%   -0.04%     
==========================================
  Files          63       63              
  Lines        3083     3083              
  Branches      574      574              
==========================================
- Hits         2099     2098       -1     
  Misses        801      801              
- Partials      183      184       +1     

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[mserico]

@copilot fix failed CI check: https://github.com/casbin/jcasbin/actions/runs/21278285214/job/61242865399?pr=507

Progress (1): 98/192 kB
Progress (1): 114/192 kB
Progress (1): 131/192 kB
Progress (1): 147/192 kB
Progress (1): 163/192 kB
Progress (1): 180/192 kB
Progress (1): 192 kB    
                    
Downloaded from central: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/4.0.0/plexus-utils-4.0.0.jar (192 kB at 3.3 MB/s)
[INFO] Recompiling the module because of changed source code.
[INFO] Compiling 78 source files with javac [debug target 1.8] to target/classes
[INFO] /home/runner/work/jcasbin/jcasbin/src/main/java/org/casbin/jcasbin/effect/DefaultEffector.java: Some input files use or override a deprecated API.
[INFO] /home/runner/work/jcasbin/jcasbin/src/main/java/org/casbin/jcasbin/effect/DefaultEffector.java: Recompile with -Xlint:deprecation for details.
[INFO] 
[INFO] --- resources:3.3.1:testResources (default-testResources) @ jcasbin ---
[INFO] skip non existing resourceDirectory /home/runner/work/jcasbin/jcasbin/src/test/resources
[INFO] 
[INFO] --- compiler:3.13.0:testCompile (default-testCompile) @ jcasbin ---
[INFO] Recompiling the module because of changed dependency.
[INFO] Compiling 33 source files with javac [debug target 1.8] to target/test-classes
[INFO] -------------------------------------------------------------
Error:  COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
Error:  /home/runner/work/jcasbin/jcasbin/src/test/java/org/casbin/jcasbin/main/AbacAPIUnitTest.java:[18,30] cannot access org.testng.annotations.Test
  bad class file: /home/runner/.m2/repository/org/testng/testng/7.10.2/testng-7.10.2.jar(org/testng/annotations/Test.class)
    class file has wrong version 55.0, should be 52.0
    Please remove or make sure it appears in the correct subdirectory of the classpath.
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  9.039 s
[INFO] Finished at: 2026-01-23T07:40:05Z
[INFO] ------------------------------------------------------------------------
Error:  Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.13.0:testCompile (default-testCompile) on project jcasbin: Compilation failure
Error:  /home/runner/work/jcasbin/jcasbin/src/test/java/org/casbin/jcasbin/main/AbacAPIUnitTest.java:[18,30] cannot access org.testng.annotations.Test
Error:    bad class file: /home/runner/.m2/repository/org/testng/testng/7.10.2/testng-7.10.2.jar(org/testng/annotations/Test.class)
Error:      class file has wrong version 55.0, should be 52.0
Error:      Please remove or make sure it appears in the correct subdirectory of the classpath.
Error:  
Error:  -> [Help 1]
Error:  
Error:  To see the full stack trace of the errors, re-run Maven with the -e switch.
Error:  Re-run Maven using the -X switch to enable full debug logging.
Error:  
Error:  For more information about the errors and possible solutions, please read the following articles:
Error:  [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
Error: Process completed with exit code 1.

[Copilot]

@copilot fix failed CI check: https://github.com/casbin/jcasbin/actions/runs/21278285214/job/61242865399?pr=507

...

Fixed in commit 65f4d65. The issue was that TestNG 7.10.2 requires Java 11+, but the project uses Java 8. Downgraded to TestNG 7.4.0 (the last version supporting Java 8) and fixed API compatibility issues. All 254 tests now pass.