Perhaps not what you came to hear, but: have you asked the maintainers/developers? They are the ones who should release it.
Cartographer is not packaged with it "out of the box" like in Melodic
pedantic, but Cartographer never "came packaged" with any ROS version.
It's not part of any of the standard variants described in REP 150 (ROS Melodic and Newer Metapackages), so whether it is available for any ROS version will depend on whether the developers/maintainers have released it.
Edit: and according to one of the maintainers (from cartographer-project/cartographer_ros#1512):
We plan to release for Noetic, but it's not yet fixed when and how we want to do it.
Originally posted by gvdhoorn with karma: 86574 on 2020-11-10
This answer was ACCEPTED on the original site
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Comment by Py on 2020-11-11:
Ok thanks for clearing this up. Much appreciated :)