Use CMake's Sphinx detection (#594) #3817

Job	Run time
pre-commit / pre-commit	1m 7s
ubuntu / gcc-build (ubuntu-24.04-arm, Release)	1m 4s
ubuntu / gcc-build (ubuntu-24.04, Debug)	57s
ubuntu / gcc-build (ubuntu-24.04, Release)	1m 0s
ubuntu / clang-build (ubuntu-24.04)	58s
ubuntu / clang-build (ubuntu-24.04-arm)	1m 7s
windows / msvc-build (Debug)	2m 50s
windows / clang-build	3m 44s
windows / msvc-build (Release)	2m 27s
mac / clang-build (Release)	2m 5s
ubuntu / gcc-build (ubuntu-24.04-arm, Debug)	1m 4s
mac / clang-build (Debug)	2m 49s
mac / clang-test	5m 33s
windows / msvc-test	4m 50s
windows / clang-test	2m 54s
ubuntu / gcc-test (ubuntu-24.04)	8m 22s
ubuntu / gcc-test (ubuntu-24.04-arm)	8m 18s
ubuntu / clang-sanitizer-build (ubuntu-24.04)	1m 4s
ubuntu / clang-test (ubuntu-24.04)	8m 33s
ubuntu / clang-test (ubuntu-24.04-arm)	8m 15s
windows / clang-test-extended	3m 17s
mac / clang-test-extended	3m 4s
windows / msvc-test-extended	3m 23s
ubuntu / clang-sanitizer-test (ubuntu-24.04)	2m 57s
ubuntu / clang-sanitizer-test-extended (ubuntu-24.04)	2m 54s
ubuntu / gcc-test-extended (ubuntu-24.04)	4m 28s
ubuntu / gcc-test-extended (ubuntu-24.04-arm)	4m 35s
ubuntu / clang-test-extended (ubuntu-24.04)	4m 30s
ubuntu / clang-test-extended (ubuntu-24.04-arm)	4m 29s
ubuntu / gcc-build-codecov	6m 5s
perf / ubuntu-gcc-build-perf-stats	1m 35s
perf / macos-clang-build-perf-stats	1m 59s
pages / build-doxygen-xml	24s
pages / build-scoreboard	19s
pages / build-sphinx	1m 4s
pages / deploy-pages	-1s
	1h 54m 3s

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