Please branch and build python3-basemap in epel9. Note: the package (called python-basemap in some releases, python3-basemap in others) is available in epel8, but for some reason not in epel9. Enabling crb, epel, and epel-next on el9 does not bring it out.
python-basemap requires numpy, which isn't yet in EPEL-9. numpy in turn requires python-meson-python. Please file a bug to request that and have it block this bug. Thank you!
*** This bug has been marked as a duplicate of bug 2099662 ***