Remove dead headers #3545

Job	Run time
dependencies (linux, gcc, Debug)	3m 17s
dependencies (linux, gcc, Release)	2m 10s
dependencies (linux, clang, Debug)	2m 45s
dependencies (linux, clang, Release)	2m 14s
conan	2m 44s
test (linux, gcc, Debug)	11m 10s
test (linux, gcc, Debug, -Dunity=ON)	7m 53s
test (linux, gcc, Release)	11m 45s
test (linux, gcc, Release, -Dunity=ON)	8m 16s
coverage (linux, gcc, Debug)	12m 57s
test (linux, clang, Debug)	8m 55s
test (linux, clang, Debug, -Dunity=ON)	6m 13s
test (linux, clang, Release)	10m 48s
test (linux, clang, Release, -Dunity=ON)	8m 11s
	1h 39m 18s

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