feat: Add support for RND power supplies

A very limited port of this:
https://github.com/rumpelsepp/opennetzteil/blob/master/devices/rnd/rnd320.go

However, these devices are so buggy that only switch on/off works
reliably … (in most cases).

contrib/rnd.rules

@@ -0,0 +1,5 @@
+# SPDX-FileCopyrightText: AISEC Pentesting Team
+#
+# SPDX-License-Identifier: CC0-1.0
+
+KERNEL=="ttyACM[0-9]*", SUBSYSTEM=="tty", SUBSYSTEMS=="usb", ATTRS{idVendor}=="0416", ATTRS{idProduct}=="5011", SYMLINK+="rnd-netzteil"

src/gallia/power_supply/devices/rnd.py

@@ -0,0 +1,67 @@
+# SPDX-FileCopyrightText: AISEC Pentesting Team
+#
+# SPDX-License-Identifier: Apache-2.0
+
+import asyncio
+from pathlib import Path
+from typing import Any
+
+from gallia.power_supply.base import BasePowerSupplyDriver
+from gallia.power_supply.exceptions import OperationNotSupportedError
+
+
+class RND320(BasePowerSupplyDriver):
+    PRODUCT_ID = "RND320"
+
+    def _send(self, data: str) -> None:
+        with Path(self.target.path).open("w") as f:
+            f.write(data)
+
+    async def get_ident(self) -> str:
+        raise OperationNotSupportedError
+
+    async def get_master(self) -> bool:
+        raise OperationNotSupportedError
+
+    async def set_master(self, enabled: bool) -> None:
+        cmd = "OUT1" if enabled else "OUT0"
+        await asyncio.to_thread(self._send, cmd)
+
+    async def get_channels(self) -> int:
+        return 1
+
+    async def get_current(self, channel: int) -> float:
+        raise OperationNotSupportedError
+
+    async def set_current(self, channel: int, value: float) -> None:
+        raise OperationNotSupportedError
+
+    async def get_voltage(self, channel: int) -> float:
+        raise OperationNotSupportedError
+
+    async def set_voltage(self, channel: int, value: float) -> None:
+        raise OperationNotSupportedError
+
+    async def get_output(self, channel: int) -> bool:
+        raise OperationNotSupportedError
+
+    async def set_output(self, channel: int, enabled: bool) -> None:
+        await self.set_master(enabled)
+
+    async def status(self) -> dict[str, Any]:
+        raise OperationNotSupportedError
+
+    async def get_ocp(self, channel: int) -> bool:
+        raise OperationNotSupportedError
+
+    async def set_ocp(self, channel: int, enabled: bool) -> None:
+        raise OperationNotSupportedError
+
+    async def get_ovp(self, channel: int) -> bool:
+        raise OperationNotSupportedError
+
+    async def set_ovp(self, channel: int, enabled: bool) -> None:
+        raise OperationNotSupportedError
+
+    async def set_beep(self, enabled: bool) -> None:
+        raise OperationNotSupportedError