🐛 fix: fix: prevent pacman -Su during ISO installation

The packages.conf generated by _configure_package_settings() in
install_service.py had update_system and update_db set to true, which
caused Calamares to run 'pacman -Su --noconfirm --disable-download-timeout'
during installation. This attempted to upgrade all system packages from
remote repositories, which is incorrect for an offline ISO installation.

Changes in packages.conf generation:
- update_system: true → false (prevents pacman -Su)
- update_db: true → false (prevents pacman -Sy)
- skip_if_no_internet: false → true (skip package ops if offline)

The package module should only perform local install/remove operations
specified in the operations block, not full system upgrades.

Author: talesam

biglinux-livecd/usr/share/biglinux/calamares/src/services/install_service.py

@@ -226,9 +226,9 @@ def _configure_package_settings(self) -> bool:
 
 backend: pacman
 
-skip_if_no_internet: false
-update_db: true
-update_system: true
+skip_if_no_internet: true
+update_db: false
+update_system: false
 
 pacman:
     num_retries: 10