[BREAKING CHANGE] Move to C++20 - Improve compile times #66

Job	Run time
macosx (clang, x86_osx, Debug)	17s
macosx (clang, x86_osx, Release)	20s
dpcpp (dpcpp, x86, Debug)	54s
clang (clang, x86, Debug)	2m 48s
dpcpp (dpcpp, sycl, Debug)	1m 3s
clang-cl (Debug)	1m 37s
clang (clang, x86, Release)	2m 44s
dpcpp (dpcpp, x86, Release)	54s
clang-cl (Release)	48s
dpcpp (dpcpp, sycl, Release)	1m 1s
gcc (gcc, x86, Debug)	2m 50s
gcc (gcc, x86, Release)	2m 48s
msvc (Debug)	1m 7s
gcc (gcc, aarch64, -Wno-psabi, Debug)	2m 49s
riscv (clang, rvv128, Debug)	2m 52s
msvc (Release)	1m 8s
nvcc	6m 26s
gcc (gcc, aarch64, -Wno-psabi, Release)	2m 45s
riscv (clang, rvv128, Release)	2m 56s
gcc (gcc, aarch64.sve, -Wno-psabi, Debug)	2m 50s
wasm (clang, wasm, Debug)	3m 11s
gcc (gcc, aarch64.sve, -Wno-psabi, Release)	2m 51s
gcc (gcc, aarch64.sve2, -Wno-psabi, Debug)	2m 46s
wasm (clang, wasm, Release)	3m 38s
gcc (gcc, aarch64.sve2, -Wno-psabi, Release)	2m 51s
gcc (gcc, ppc64, -Wno-psabi, Debug)	2m 50s
gcc (gcc, ppc64, -Wno-psabi, Release)	2m 49s
	1h 1m 53s

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