Introduce `halfspace_matrix_pair(ZZ, ...)` #19225

Job	Run time
book-tests (1.10)	1h 20m 15s
doctest (1.10, ubuntu-latest)	34m 52s
book-tests (pre)	44m 47s
doctest (1.11, ubuntu-latest)	33m 35s
book-tests (nightly)	43m 19s
extra-long-test	0s
doctest (1.12-nightly, ubuntu-latest)	39m 4s
doctest (nightly, ubuntu-latest)	40m 20s
test (1.6, short, Linux)	21m 36s
doctest (1.10, ubuntu-latest, depwarn=error)	33m 50s
test (1.6, long, Linux)	18m 43s
doctest (1.10, macOS, RPTU)	17m 45s
test (1.10, short, Linux)	27m 14s
test (1.10, long, Linux)	18m 28s
test (1.11, short, Linux)	23m 34s
test (1.11, long, Linux)	15m 37s
test (1.12-nightly, short, Linux)	24m 53s
test (1.12-nightly, long, Linux)	21m 14s
test (nightly, short, Linux)	12m 1s
test (nightly, long, Linux)	15m 32s
test (1.10, short, Linux, RPTU, high-memory, depwarn=error)	22m 15s
test (1.10, long, Linux, RPTU, normal-memory, depwarn=error)	18m 14s
test (1.10, short, macOS, RPTU)	14m 5s
test (1.10, long, macOS, RPTU)	12m 16s
Send Slack notification on status change	0s
	10h 33m 29s

Provide feedback