Use CMake's Sphinx detection #3806

Job	Run time
pre-commit / pre-commit	1m 33s
ubuntu / clang-build (ubuntu-24.04-arm)	1m 3s
mac / clang-build (Debug)	3m 0s
ubuntu / gcc-build (ubuntu-24.04, Debug)	51s
ubuntu / clang-build (ubuntu-24.04)	54s
mac / clang-build (Release)	2m 43s
ubuntu / gcc-build (ubuntu-24.04-arm, Release)	1m 7s
ubuntu / gcc-build (ubuntu-24.04-arm, Debug)	58s
ubuntu / gcc-build (ubuntu-24.04, Release)	1m 1s
windows / clang-build	3m 26s
windows / msvc-build (Release)	1m 41s
windows / msvc-build (Debug)	2m 42s
mac / clang-test	4m 54s
ubuntu / clang-test (ubuntu-24.04)	8m 28s
ubuntu / clang-sanitizer-build (ubuntu-24.04)	1m 0s
ubuntu / clang-test (ubuntu-24.04-arm)	8m 23s
mac / clang-test-extended	2m 56s
windows / msvc-test	4m 50s
windows / clang-test	3m 18s
ubuntu / gcc-test (ubuntu-24.04)	8m 21s
ubuntu / gcc-test (ubuntu-24.04-arm)	8m 23s
ubuntu / clang-sanitizer-test (ubuntu-24.04)	2m 50s
ubuntu / clang-sanitizer-test-extended (ubuntu-24.04)	2m 25s
windows / clang-test-extended	3m 8s
windows / msvc-test-extended	3m 18s
ubuntu / clang-test-extended (ubuntu-24.04-arm)	4m 25s
ubuntu / clang-test-extended (ubuntu-24.04)	4m 33s
ubuntu / gcc-test-extended (ubuntu-24.04-arm)	4m 27s
ubuntu / gcc-test-extended (ubuntu-24.04)	4m 28s
ubuntu / gcc-build-codecov	6m 18s
perf / ubuntu-gcc-build-perf-stats	1m 36s
perf / macos-clang-build-perf-stats	2m 5s
pages / build-doxygen-xml	22s
pages / build-scoreboard	15s
pages / build-sphinx	34s
pages / deploy-pages	0s
	1h 52m 16s

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