bump up container image versions and drop using CPack

We have already provided DEB packages in launchpad PPA and RPM packages
in COPR. Thus, we need no more deb/rpm packages in Github releases. The
single binary build of mscp is an execptio.

Updated container image versions:
- almalinux	8.8  -> 9.3
- rocky		8.8  -> 8.9, and 9.3 is added
- alpine	3.17 -> 3.19

Dockerfile/build-srpm.Dockerfile.in

@@ -0,0 +1,22 @@
+FROM rockylinux:9
+
+# install pytest, sshd for test, and rpm-build
+RUN set -ex && yum -y install rpm-build rpmdevtools
+
+ARG mscpdir="/mscp-@MSCP_VERSION@"
+ARG mscptgz="mscp-@MSCP_VERSION@.tar.gz"
+
+COPY . ${mscpdir}
+
+# install build dependency
+RUN ${mscpdir}/scripts/install-build-deps.sh
+
+# prepare rpmbuild
+RUN rpmdev-setuptree \
+	&& rm -rf ${mscpdir}/build	\
+	&& tar zcvf /${mscptgz} --exclude-vcs ${mscpdir}	\
+	&& cp /${mscptgz} ~/rpmbuild/SOURCES/	\
+	&& cp ${mscpdir}/rpm/mscp.spec ~/rpmbuild/SPECS/
+
+# build rpm and src.rpm
+RUN rpmbuild -ba ~/rpmbuild/SPECS/mscp.spec