Don't always require all headers from all versions of BoringSSL #1580

Job	Run time
Cross build from macOS to Linux (x86_64-unknown-linux-gnu)	2m 55s
Test FIPS integration	3m 46s
clippy	1m 43s
Test features	3m 27s
rustfmt	7s
Test (aarch64-ios-sim)	2m 51s
Test (aarch64-ios)	3m 30s
Test (stable)	2m 31s
Test (arm-linux)	3m 8s
Test (i686-android)	2m 58s
Test (x86_64-android)	2m 41s
Test (aarch64-linux)	3m 33s
Test (arm64-android)	3m 10s
Test (x86_64-ios)	3m 2s
Test (x86_64-msvc)	7m 38s
Test (i686-mingw)	10m 33s
Test (arm-android)	2m 50s
Test (i686-linux)	3m 13s
Test (i686-msvc)	9m 18s
Test (arm64-macos)	2m 9s
Test (x86_64-macos)	2m 37s
Test (x86_64-mingw)	7m 59s
	1h 25m 39s

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