RHEL9: unable to install usermin via webmin's repo (setup-repos.sh)

[defung]

Installation of usermin fails with GPG error when installing it from the repo. This can be reproduced in docker, using rockylinux:9.

Steps to reproduce:

1. Run container:

docker run -it --rm rockylinux:9

2. Install script dependencies (tput):

dnf install ncurses

3. Download and run webmin's setup-repos.sh script:

curl -o setup-repos.sh https://raw.githubusercontent.com/webmin/webmin/master/setup-repos.sh
sh setup-repos.sh

4. Install usermin:

dnf install usermin

You will get the following error:

GPG key at file:///etc/pki/rpm-gpg/RPM-GPG-KEY-webmin-developers (0x8916F2A2) is already installed
The GPG keys listed for the "Webmin - noarch" repository are already installed but they are not correct for this package.
Check that the correct key URLs are configured
for this repository.. Failing package is: usermin-1.861-1.noarch
 GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-webmin-developers
The downloaded packages were saved in cache until the next successful transaction.
You can remove cached packages by executing 'dnf clean packages'.
Error: GPG check FAILED