cli: remove some dead code #2436

Job	Run time
testfull-regex	3m 50s
msrv	1m 6s
rustfmt	7s
miri-regex-automata	14m 52s
testfull-regex-automata	9m 4s
test (stable, ubuntu-latest, stable)	3m 47s
testfull-regex-capi	30s
test (stable-32, ubuntu-latest, stable, i686-unknown-linux-gnu)	3m 5s
testfull-regex-syntax	2m 2s
test (stable-powerpc64, ubuntu-latest, stable, powerpc64-unknown-linux-gnu)	7m 25s
test (stable-s390x, ubuntu-latest, stable, s390x-unknown-linux-gnu)	9m 7s
test (beta, ubuntu-latest, beta)	3m 39s
test (nightly, ubuntu-latest, nightly)	2m 53s
test (macos, macos-latest, stable)	2m 25s
test (win-msvc, windows-latest, stable)	6m 48s
test (win-gnu, windows-latest, stable-x86_64-gnu)	3m 32s
	1h 14m 12s

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