drop centos8, add almalinux 8.8, update rocky to 8.8

And cleanup Docker files

docker/alpine-3.17.Dockerfile

@@ -2,18 +2,26 @@ FROM alpine:3.17
 
 # Build mscp with conan to create single binary mscp
 
-ARG mscpdir="/mscp"
-
-COPY . ${mscpdir}
-
 RUN apk add --no-cache \
 	gcc make cmake python3 py3-pip perl linux-headers libc-dev	\
 	openssh bash python3-dev g++
 
 RUN pip3 install conan pytest
 
+# preparation for sshd
+RUN ssh-keygen -A
+RUN  mkdir /var/run/sshd        \
+        && ssh-keygen -f /root/.ssh/id_rsa -N ""                \
+        && mv /root/.ssh/id_rsa.pub /root/.ssh/authorized_keys
+
+
 # Build mscp as a single binary
 RUN conan profile detect --force
+
+ARG mscpdir="/mscp"
+
+COPY . ${mscpdir}
+
 RUN cd ${mscpdir}							\
 	&& rm -rf build							\
 	&& conan install . --output-folder=build --build=missing	\
@@ -25,15 +33,8 @@ RUN cd ${mscpdir}							\
 	&& make								\
 	&& cp mscp /usr/bin/						\
 	&& cp mscp /mscp/build/mscp_alpine-3.17-x86_64.static
-
 # copy mscp to PKG FILE NAME because this build doesn't use CPACK
 
-# preparation for sshd
-RUN ssh-keygen -A
-RUN  mkdir /var/run/sshd        \
-        && ssh-keygen -f /root/.ssh/id_rsa -N ""                \
-        && mv /root/.ssh/id_rsa.pub /root/.ssh/authorized_keys
-
 # install mscp python module
 RUN cd ${mscpdir}	\
 	&& python3 setup.py install --user