Treat position bias via GAM in LambdaMART #6989

Job	Run time
r-package (ubuntu-latest, gcc, R 3.6, cmake)	10m 39s
r-package (ubuntu-latest, gcc, R 4.2, cmake)	10m 37s
r-package (ubuntu-latest, clang, R 3.6, cmake)	10m 39s
r-package (ubuntu-latest, clang, R 4.2, cmake)	10m 40s
r-package (macOS-latest, gcc, R 4.2, cmake)	10m 44s
r-package (macOS-latest, clang, R 4.2, cmake)	10m 43s
r-package (windows-latest, MINGW, R 3.6, cmake)	10m 38s
r-package (windows-latest, MINGW, R 4.2, cmake)	10m 41s
r-package (windows-2019, MSVC, R 3.6, cmake)	11m 3s
r-package (windows-2022, MSVC, R 4.2, cmake)	11m 13s
r-package (windows-latest, MINGW, R 3.6, cran)	10m 40s
r-package (windows-latest, MINGW, R 4.2, cran)	10m 42s
r-package (ubuntu-latest, gcc, R 4.2, cran)	10m 38s
r-package (macOS-latest, clang, R 4.2, cran)	10m 48s
r-rchk (ubuntu-latest, gcc, R 4.2, cran)	10m 40s
r-package (debian, R-devel, clang)	10m 36s
r-sanitizers (ubuntu-latest, R-devel, gcc ASAN/UBSAN)	10m 36s
r-sanitizers (ubuntu-latest, R-devel, clang ASAN/UBSAN)	10m 34s
all-r-package-jobs-successful	2s
	3h 12m 53s

Provide feedback