Removed constcat requirement #1013

Job	Run time
build-cross-targets (aarch64-unknown-linux-gnu)	2m 10s
build (macos-latest, --all-features)	1m 40s
build-coverage	2m 57s
build-cross-targets (armv7-unknown-linux-gnueabihf)	2m 29s
build-ffi	2m 27s
build (macos-latest, --no-default-features)	1m 52s
build-cross-targets (i686-unknown-linux-gnu)	2m 6s
build (ubuntu-latest, --all-features)	1m 21s
build (ubuntu-latest, --no-default-features)	1m 17s
build (windows-latest, --all-features)	2m 25s
build (windows-latest, --no-default-features)	2m 26s
lint	1m 8s
build-nostd (macos-latest)	55s
test (macos-latest)	1m 41s
build-nostd (ubuntu-latest)	34s
test (ubuntu-latest)	1m 28s
build-nostd (windows-latest)	41s
test (windows-latest)	1m 33s
test-cross (aarch64-unknown-linux-gnu)	2m 30s
test-cross (i686-unknown-linux-gnu)	1m 57s
	35m 37s

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