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/config_mixin.py

@@ -19,7 +19,6 @@ from __future__ import annotations
 import re
 from typing import Any
 
-
 _JsonDict = dict[str, Any]
 
 
@@ -44,13 +43,9 @@ class ProxmoxConfigMixin:
         configs: _JsonDict = {"running": "", "candidate": "", "startup": ""}
 
         if retrieve in ("running", "all", "startup"):
-            raw = self._exec_ssh_command(
-                "cat /etc/network/interfaces 2>/dev/null || true"
-            )
+            raw = self._exec_ssh_command("cat /etc/network/interfaces 2>/dev/null || true")
             # Append SDN config if available
-            sdn_raw = self._exec_ssh_command(
-                "cat /etc/pve/sdn/vnets.cfg 2>/dev/null || true"
-            )
+            sdn_raw = self._exec_ssh_command("cat /etc/pve/sdn/vnets.cfg 2>/dev/null || true")
             running = raw
             if sdn_raw:
                 running += "\n# === SDN VNets ===\n" + sdn_raw