Bump xuantie toolchains #6037

Job	Run time
build (ubuntu-latest, flang, cmake)	19m 25s
neoverse_build	7m 49s
build (macos-latest, gfortran, cmake)	37m 23s
msys2 (CLANG64, int32, Release)	31m 42s
build (ubuntu-latest, flang, make)	9m 5s
msys2 (UCRT64, int32, None, mingw-w64-ucrt-x86_64, fc)	40m 56s
msys2 (UCRT64, int32, Release)	43m 58s
build (macos-latest, gfortran, make)	8m 54s
cross_build (mipsel, mipsel-linux-gnu, TARGET=MIPS1004K)	4m 29s
cross_build (alpha, alpha-linux-gnu, TARGET=EV4)	3m 34s
cross_build (mips64el, mips64el-linux-gnuabi64, DYNAMIC_ARCH=1 TARGET=GENERIC)	4m 49s
build (ubuntu-latest, gfortran, make)	26m 40s
msys2 (UCRT64, int64, Release)	44m 34s
msys2 (MINGW32, int32, Release)	36m 30s
build (ubuntu-latest, gfortran, cmake)	45m 15s
msys2 (CLANG64, int64, Release)	30m 21s
cross_build (riscv64, riscv64-linux-gnu, TARGET=RISCV64_GENERIC)	21m 20s
	6h 56m 44s

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