Fix update count for dnf4 compatibility

The fix introduced in b24592f for
dnf5 compatibility inherently broke compatibility with dnf4.

While that was fine at the time because sysmotd was only targeting
Fedora versions using dnf5, sysmotd now also targets AlmaLinux after
lolcat became available through the EPEL repository. AlmaLinux 9 and
10 still use dnf4.

So enhance the logic to parse available upgrades to accommodate dnf4
and dnf5 output formats, and also include package installs (e.g.
kernel) in the count.

Signed-off-by: Manuel Fombuena <mfombuena@innovara.tech>

Author: innovara

sysmotd/sysmotd

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 # Copyright (C) 2022-2025  Manuel Fombuena <mfombuena@innovara.tech>
 #
-# sysmotd - generates a MOTD (Message Of The Day) including system 
+# sysmotd - generates a MOTD (Message Of The Day) including system
 # information on Fedora Linux, and possibly other Red Hat-based distributions.
 #
 # This program is free software: you can redistribute it and/or modify
@@ -17,7 +17,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
-#  
+#
 
 # directory where the motd files will live
 rundir="/run/motd.d"
@@ -116,13 +116,17 @@ printf '%s %s %s %s %s\n' "${sysarray[@]}" | column -t -s $';' >> $sysinfo
 echo -e "" >> $sysinfo
 
 # available updates refreshes every 60 minutes using CACHE.
-# dnf's cache is updated by the system using its own service and timer. The conservative 
+# dnf's cache is updated by the system using its own service and timer. The conservative
 # approach is to not to change this.
 NEED_UPDATE="FALSE"
 [ -z "$(find "$updates" -newermt 'now-60 minutes' 2> /dev/null)" ] && NEED_UPDATE="TRUE"
 
 if [[ "$NEED_UPDATE" = "TRUE" ]]; then
-   n_updates=$(dnf update --assumeno --cacheonly --noplugins | awk '/^ Upgrading/ {print $2;}')
+   n_updates=$(dnf upgrade --assumeno --cacheonly --noplugins 2>/dev/null | awk '
+      /Upgrading:|Installing:|^Upgrade |^Install / { n+=$2 }
+      END { print n+0 }
+   ')
+
    if [[ $n_updates -eq 0 ]]; then
       echo -e "There were no updates available when last checked.\n" > $updates
    elif [[ $n_updates -eq 1 ]]; then