Because no versions of black match >23.1.0,<23.3.0 || >23.3.0,<24.0.0
and black (23.1.0) depends on packaging (>=22.0), black (>=23.1.0,<23.3.0 || >23.3.0,<24.0.0) requires packaging (>=22.0).
And because black (23.3.0) depends on packaging (>=22.0), black (>=23.1.0,<24.0.0) requires packaging (>=22.0).
Because no versions of tufup match >0.5.0,<0.6.0
and tufup (0.5.0) depends on packaging (==21.*), tufup (>=0.5.0,<0.6.0) requires packaging (==21.*).
Thus, tufup (>=0.5.0,<0.6.0) is incompatible with black (>=23.1.0,<24.0.0).
So, because my-app depends on both tufup (^0.5.0) and black (^23.1.0), version solving failed.