Revert replacing DNF with DNF5
The switch to DNF 5 has been postponed, likely to Fedora 41. See
https://pagure.io/fesco/issue/3039.
This reverts the following commits:
41a8487712bcece4130344b1a9e5cbb34909d3d6
d84d3e61e05160b43e12345d90f36e69d8b108fa
b24aea7e689c5473f2f9552694da31f6f856f1a4
02439d3a306da8af4103c3497de248667abe6493