Add pacstall to package managers (#1979)

neofetch

@@ -1564,6 +1564,7 @@ get_packages() {
             has butch      && tot butch list
             has swupd      && tot swupd bundle-list --quiet
             has pisi       && tot pisi li
+            has pacstall   && tot pacstall -L
 
             # Using the dnf package cache is much faster than rpm.
             if has dnf && type -p sqlite3 >/dev/null && [[ -f /var/cache/dnf/packages.db ]]; then