drop duplicate dependencies

[hboutemy]

fixes 2 warn when building mvn validate

[WARNING] Some problems were encountered while building the effective model for com.taobao.arthas:arthas-grpc-server:jar:4.0.5
[WARNING] 'dependencies.dependency.(groupId:artifactId:type:classifier)' must be unique: ch.qos.logback:logback-classic:jar -> version 1.5.0 vs (?) @ com.taobao.arthas:arthas-grpc-server:${revision}, /home/dev/labs/arthas-grpc-server/pom.xml, line 111, column 21
[WARNING] 'dependencies.dependency.(groupId:artifactId:type:classifier)' must be unique: org.slf4j:slf4j-api:jar -> version 2.0.12 vs (?) @ com.taobao.arthas:arthas-grpc-server:${revision},/home/dev/labs/arthas-grpc-server/pom.xml, line 119, column 21

[hboutemy]

[INFO] --- compiler:3.8.0:testCompile (default-testCompile) @ arthas-grpc-server ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 3 source files to /home/runner/work/arthas/arthas/labs/arthas-grpc-server/target/test-classes
[INFO] -------------------------------------------------------------
Error:  COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
Error:  /home/runner/work/arthas/arthas/labs/arthas-grpc-server/src/test/java/unittest/grpc/GrpcTest.java:[5,30] cannot access ch.qos.logback.classic.Level
  bad class file: /home/runner/.m2/repository/ch/qos/logback/logback-classic/1.5.0/logback-classic-1.5.0.jar(ch/qos/logback/classic/Level.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.

uh, something is weird in dependencies and minimum Java level