Mechanical: ruff format, and ruff check --fix with the rule set every NAPALM
driver uses (E, F, I, UP, B at line length 100, Python 3.10). What ruff
cannot fix comes in the next commit.
A Proxmox node runs its own kernel under every guest, which makes it the host
where a kernel CVE's preconditions matter most. ProxmoxDriver mixes in
KernelFactsMixin from napalm-device-types and supplies only the transport,
the existing exec path.
Requires napalm-device-types 2.1.0.