Switch to CentOS 9 and provide an image tag to fix #8

Author: ofalk

Dockerfile

@@ -1,7 +1,7 @@
-FROM docker.io/centos
+FROM quay.io/centos/centos:stream9
 
 MAINTAINER Oliver Falk <[email protected]>
 
 RUN ln -sf /dev/stdout /var/log/messages
-RUN yum -y install git gcc make libpcap-devel libdnet-devel libevent-devel automake; yum clean all
+RUN dnf -y install epel-release epel-next-release && dnf -y install git-core gcc make libpcap-devel libdnet-devel libevent-devel automake; yum clean all
 RUN pushd /var/tmp && git clone https://github.com/ofalk/scanssh.git && pushd scanssh && aclocal && automake && ./configure && make && make install