[wip] Support arrow-backed pandas categorical columns. #13715

Job	Run time
Build and test JVM packages (macos-15-intel)	14m 4s
Build and test JVM packages (windows-latest)	9m 48s
Build libxgboost4j.so targeting glibc 2.17 (arch x86_64, runner linux-amd64-cpu)	1m 53s
Build libxgboost4j.dylib for MacOS (Intel)	4m 57s
Build and test JVM packages (Linux, Scala 2.12)	10m 1s
Build libxgboost4j.so with CUDA	8m 24s
Build and test JVM packages (Linux, Scala 2.13)	4m 48s
Build libxgboost4j.dylib for MacOS (Apple Silicon)	2m 32s
Build libxgboost4j.so targeting glibc 2.17 (arch aarch64, runner linux-arm64-cpu)	2m 16s
Test JVM packages with CUDA (Scala 2.13)	8m 30s
Test JVM packages with CUDA (Scala 2.12)	8m 20s
Deploy JVM packages to S3 (gpu, Scala 2.13)	17s
Deploy JVM packages to S3 (cpu, Scala 2.12)	14s
Deploy JVM packages to S3 (gpu, Scala 2.12)	17s
Deploy JVM packages to S3 (cpu, Scala 2.13)	19s
	1h 16m 40s

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