[doc] Simplify README, incl. remove duplicates after hotfix (#689) #4354

Job	Run time
pre-commit / pre-commit	1m 16s
windows / clang-build	2m 22s
ubuntu / clang-build (ubuntu-24.04)	2m 48s
ubuntu / clang-build (ubuntu-24.04-arm)	2m 37s
mac / clang-build (Release)	2m 30s
mac / clang-build (Debug)	2m 52s
windows / msvc-build (Release)	4m 34s
windows / msvc-build (Debug)	3m 7s
ubuntu / gcc-build (ubuntu-24.04, Debug)	2m 16s
ubuntu / gcc-build (ubuntu-24.04-arm, Debug)	1m 56s
ubuntu / gcc-build (ubuntu-24.04-arm, Release)	1m 58s
ubuntu / gcc-build (ubuntu-24.04, Release)	2m 20s
windows / clang-test	3m 29s
mac / clang-test	5m 26s
windows / msvc-test	5m 1s
ubuntu / clang-sanitizer-build (ubuntu-24.04)	3m 36s
ubuntu / clang-test (ubuntu-24.04-arm)	8m 16s
ubuntu / clang-test (ubuntu-24.04)	8m 24s
ubuntu / gcc-test (ubuntu-24.04)	8m 25s
ubuntu / gcc-test (ubuntu-24.04-arm)	8m 41s
windows / clang-test-extended	2m 51s
mac / clang-test-extended	2m 53s
windows / msvc-test-extended	2m 49s
ubuntu / clang-sanitizer-test (ubuntu-24.04)	2m 56s
ubuntu / clang-test-extended (ubuntu-24.04-arm)	4m 44s
ubuntu / clang-test-extended (ubuntu-24.04)	4m 40s
ubuntu / gcc-test-extended (ubuntu-24.04-arm)	4m 28s
ubuntu / gcc-test-extended (ubuntu-24.04)	4m 29s
ubuntu / clang-sanitizer-test-extended (ubuntu-24.04)	2m 27s
ubuntu / gcc-build-codecov	7m 37s
perf / macos-clang-build-perf-stats	2m 26s
perf / ubuntu-gcc-build-perf-stats	1m 19s
pages / build-scoreboard	18s
pages / build-doxygen-xml	21s
pages / build-sphinx	54s
pages / deploy-pages	19s
	2h 7m 25s

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