In RedHat RHEL 9.x (and compatibles) SHA1 signing of the GPG keys for RPM packages has been deprecated. So if you have older keys that ARE SHA1-signed, you will get a warning whenever you use rpm/yum/dnf: warning: Signature not supported. Hash algorithm SHA1 not available
To get a list of all gpg-keys installed run the following:
rpm -q gpg-pubkey --qf '%{NAME}-%{VERSION}-%{RELEASE}:\t%{SUMMARY}\n'
Use the following command to uninstall the old SHA1-signed key:
rpm --erase --allmatches gpg-pubkey-package-as-listed-in-previous-rpm-query
To allow installation of a package that IS SHA-1 signed:
update-crypto-policies --set DEFAULT:SHA1
Then run your rpm or dnf/yum command.
Make sure to switch the crypto policies back to their default by doing the following afterward:
update-crypto-policies --set DEFAULT