style: ruff format and the lint rules of the driver standard

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.

napalm_proxmox/utils.py

@@ -14,7 +14,6 @@ from typing import Any
 
 from netaddr import EUI, AddrFormatError
 
-
 # ---------------------------------------------------------------------------
 # MAC address helpers
 # ---------------------------------------------------------------------------
@@ -47,6 +46,7 @@ def normalize_mac(mac: str) -> str:
 # IP / prefix helpers
 # ---------------------------------------------------------------------------
 
+
 def prefix_length(cidr: str) -> int:
     """Return prefix length from a CIDR string such as '192.168.1.0/24' → 24."""
     try:
@@ -141,6 +141,7 @@ def speed_mbps(iface_data: dict[str, Any]) -> float:
 # ARP / neighbour table helpers
 # ---------------------------------------------------------------------------
 
+
 def parse_arp_output(raw: str) -> list[dict[str, Any]]:
     """Parse Linux ``arp -n`` text output into NAPALM ARP dicts.
 
@@ -202,6 +203,7 @@ def sdn_zone_to_network_instance(zone: dict[str, Any]) -> dict[str, Any]:
 # OVS helpers
 # ---------------------------------------------------------------------------
 
+
 def parse_ovs_vsctl_show(raw: str) -> dict[str, Any]:
     """Very lightweight parser for ``ovs-vsctl show`` output.