Fix `provision.sh`: pacman command

[TheDcoder]

1. Remove invalid pacman update command
2. Add --upgrade to prevent partial upgrades which are unsupported in Arch Linux

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...) Bug fix

• What is the current behavior? (You can also link to an open issue here) Faulty, pacman doesn't have an update sub-command and partial upgrades may break the system.

• What is the new behavior (if this is a feature change)? Correct without invalid commands and full upgrade.

• Other information: None

[TheDcoder]

scripts/partials/basic-deps seems to be out of sync since scripts/provision.sh has a different set of packages compared to the partial:

curl expect git rsync vs. base-devel curl expect git rsync procps-ng file

[ProfessorManhattan]

Merged this manually