fix(script): stop running full system upgrades via pacman -Syu on Arch

Installing or updating the panel on Arch/Manjaro/Parch performed a full
system upgrade (pacman -Syu) instead of only refreshing the package
database and installing the needed packages, unlike every other distro
branch (apt-get update, dnf makecache, zypper refresh, apk update).
Unrequested full upgrades can pull in kernel and system updates the
user never asked for. Align all pacman calls on the -Sy --noconfirm
form already used elsewhere in these scripts.

Closes #5810

install.sh

@@ -111,7 +111,7 @@ install_base() {
             fi
             ;;
         arch | manjaro | parch)
-            pacman -Syu && pacman -Syu --noconfirm cronie curl tar tzdata socat ca-certificates openssl
+            pacman -Sy --noconfirm cronie curl tar tzdata socat ca-certificates openssl
             ;;
         opensuse-tumbleweed | opensuse-leap)
             zypper refresh && zypper -q install -y cron curl tar timezone socat ca-certificates openssl
@@ -204,7 +204,7 @@ install_postgres_local() {
             [[ -d /var/lib/pgsql/data && -f /var/lib/pgsql/data/PG_VERSION ]] || postgresql-setup --initdb >&2 || return 1
             ;;
         arch | manjaro | parch)
-            pacman -Syu --noconfirm postgresql >&2 || return 1
+            pacman -Sy --noconfirm postgresql >&2 || return 1
             if [[ ! -f /var/lib/postgres/data/PG_VERSION ]]; then
                 sudo -u postgres initdb -D /var/lib/postgres/data >&2 || return 1
             fi

update.sh

@@ -193,7 +193,7 @@ install_base() {
             fi
             ;;
         arch | manjaro | parch)
-            pacman -Syu > /dev/null 2>&1 && pacman -Syu --noconfirm cronie curl tar tzdata socat openssl > /dev/null 2>&1
+            pacman -Sy --noconfirm cronie curl tar tzdata socat openssl > /dev/null 2>&1
             ;;
         opensuse-tumbleweed | opensuse-leap)
             zypper refresh > /dev/null 2>&1 && zypper -q install -y cron curl tar timezone socat openssl > /dev/null 2>&1

x-ui.sh

@@ -2297,7 +2297,7 @@ setup_fail2ban_iplimit() {
                 fi
                 ;;
             arch | manjaro | parch)
-                pacman -Syu --noconfirm fail2ban nftables
+                pacman -Sy --noconfirm fail2ban nftables
                 ;;
             alpine)
                 apk add fail2ban nftables
@@ -2874,7 +2874,7 @@ pg_install_local() {
             [[ -d /var/lib/pgsql/data && -f /var/lib/pgsql/data/PG_VERSION ]] || postgresql-setup --initdb >&2 || return 1
             ;;
         arch | manjaro | parch)
-            pacman -Syu --noconfirm postgresql >&2 || return 1
+            pacman -Sy --noconfirm postgresql >&2 || return 1
             if [[ ! -f /var/lib/postgres/data/PG_VERSION ]]; then
                 sudo -u postgres initdb -D /var/lib/postgres/data >&2 || return 1
             fi