Zigbee2MQTT: fix: pnpm workspace in update (#8825)

Author: fkroeger

ct/zigbee2mqtt.sh

@@ -47,7 +47,7 @@ function update_script() {
     rm -rf /opt/zigbee2mqtt/data
     mv /opt/z2m_backup/data /opt/zigbee2mqtt
     cd /opt/zigbee2mqtt
-    echo "packageImportMethod: hardlink" >>./pnpm-workspace.yaml
+    grep -q "^packageImportMethod" ./pnpm-workspace.yaml || echo "packageImportMethod: hardlink" >> ./pnpm-workspace.yaml
     $STD pnpm install --frozen-lockfile
     $STD pnpm build
     msg_ok "Updated Zigbee2MQTT"