[R] Fix winbuilder check warnings. #13832

Job	Run time
Build libxgboost4j.so targeting glibc 2.17 (arch x86_64, runner linux-amd64-cpu)	2m 6s
Build libxgboost4j.so targeting glibc 2.17 (arch aarch64, runner linux-arm64-cpu)	2m 14s
Build and test JVM packages (Linux, Scala 2.12)	10m 55s
Build and test JVM packages (Linux, Scala 2.13)	5m 34s
Build libxgboost4j.dylib for MacOS (Intel)	4m 28s
Build and test JVM packages (windows-latest)	9m 23s
Build libxgboost4j.dylib for MacOS (Apple Silicon)	2m 27s
Build and test JVM packages (macos-15-intel)	10m 6s
Build libxgboost4j.so with CUDA	7m 44s
Test JVM packages with CUDA (Scala 2.13)	8m 34s
Test JVM packages with CUDA (Scala 2.12)	8m 32s
Deploy JVM packages to S3 (cpu, Scala 2.13)	14s
Deploy JVM packages to S3 (gpu, Scala 2.12)	18s
Deploy JVM packages to S3 (cpu, Scala 2.12)	14s
Deploy JVM packages to S3 (gpu, Scala 2.13)	16s
	1h 13m 5s

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