[_library.py] implement array_jit decorator correctly

Fixes #64
8 jobs for issue-64 in 11 minutes and 15 seconds (queued for 7 seconds)
Status Name Job ID Coverage
  Build
passed build_linux_37 #238051
docker

00:09:23

80.0%
passed build_linux_38 #238052
docker

00:09:39

81.0%
passed build_macos_intel_37 #238049
macos intel

00:11:15

80.0%
passed build_macos_intel_38 #238050
macos intel

00:11:13

81.0%
failed build_linux_37 #237965
docker

00:21:11

failed build_linux_38 #237966
docker

00:21:14

failed build_macos_intel_37 #237963
macos intel

00:18:25

failed build_macos_intel_38 #237964
macos intel

00:18:41