[docs] remove links to Laurae++ site #7610

Job	Run time
r-package (debian, R-devel, clang)	13m 16s
r-package (ubuntu-latest, gcc, R 3.6, cmake)	10m 54s
r-package (ubuntu-latest, gcc, R 4.3, cmake)	10m 1s
r-sanitizers (ubuntu-latest, R-devel, gcc ASAN/UBSAN)	15m 7s
r-package (ubuntu-latest, clang, R 3.6, cmake)	11m 33s
r-sanitizers (ubuntu-latest, R-devel, clang ASAN/UBSAN)	30m 47s
r-package (ubuntu-latest, clang, R 4.3, cmake)	9m 59s
r-package (macOS-latest, gcc, R 4.3, cmake)	15m 21s
r-package (macOS-latest, clang, R 4.3, cmake)	10m 51s
r-package (windows-latest, MINGW, R 3.6, cmake)	16m 9s
r-package (windows-latest, MINGW, R 4.3, cmake)	21m 28s
r-package (windows-2019, MSVC, R 3.6, cmake)	14m 26s
r-package (windows-2022, MSVC, R 4.3, cmake)	17m 54s
r-package (windows-latest, MINGW, R 3.6, cran)	24m 42s
r-package (windows-latest, MINGW, R 4.3, cran)	23m 32s
r-package (ubuntu-latest, gcc, R 4.3, cran)	15m 3s
r-package (macOS-latest, clang, R 4.3, cran)	23m 53s
r-rchk (ubuntu-latest, gcc, R 4.3, cran)	9m 46s
all-r-package-jobs-successful	4s
	4h 54m 46s

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