ci: Fix kernel downgrade to let scriptlets run with TMPDIR=/var/tmp

Undo hacky --noscripts - this was working around an rpm-ostree
bug (working on a PR for that).

Assisted-by: OpenCode (claude-sonnet-4-6@default)
Signed-off-by: Colin Walters <walters@verbum.org>

Author: cgwalters

hack/provision-fetch.sh

@@ -155,21 +155,10 @@ case "${kernel_ver}" in
                 "${koji_base}/${pkg}-${koji_kver}-${koji_krel}.${arch}.rpm" \
                 -o "${kernel_td}/${pkg}.rpm"
         done
-        # Skip scriptlets: kernel-core's posttrans runs `kernel-install add`
-        # which calls rpm-ostree, and that fails inside a container build.
-        # We manually run depmod afterward since it's the only useful
-        # scriptlet the kernel packages would otherwise execute.
-        dnf -y install --allowerasing --setopt=tsflags=noscripts "${kernel_td}"/*.rpm
-        /sbin/depmod -a "${koji_kver}-${koji_krel}.$(uname -m)"
-        # Remove any leftover module directories for the old kernel (e.g.
-        # initramfs.img generated by the base image build is not RPM-owned
-        # so dnf does not clean it up).
-        for old_kmod_dir in /usr/lib/modules/*; do
-            kd_ver=$(basename "${old_kmod_dir}")
-            if [[ "${kd_ver}" != "${koji_kver}-"* ]]; then
-                rm -rf "${old_kmod_dir}"
-            fi
-        done
+        # TMPDIR=/var/tmp: works around an rpm-ostree bug
+        TMPDIR=/var/tmp dnf -y downgrade "${kernel_td}"/*.rpm
+        # Note: we should also fix the Fedora kernel packaging to not copy symvers into /boot
+        rm -rf /boot/*
         rm -rf "${kernel_td}"
         trap - EXIT
         ;;

tmt/tests/Dockerfile.upgrade-source

@@ -40,15 +40,6 @@ if [[ "${variant}" == composefs* ]]; then
     echo 'add_dracutmodules+=" bootc "' > /etc/dracut.conf.d/50-bootc-composefs.conf
     kver=$(cd /usr/lib/modules && echo *)
     dracut --force --kver "$kver" "/usr/lib/modules/$kver/initramfs.img"
-else
-    . /usr/lib/os-release
-
-    if [[ $ID == "fedora" && $VERSION_ID == "44" ]]; then
-        # We skip kernel postinstall in "provision-fetch" which would've generated
-        # the initrd, so we do it ourselves here
-        kver=$(cd /usr/lib/modules && echo *)
-        dracut --force --kver "$kver" "/usr/lib/modules/$kver/initramfs.img"
-    fi
 fi
 
 rm -rf /run/provision