fix: define ret as Optional[str] before reassignment in get_fido2_devices (#1894)

archinstall/lib/disk/fido.py

@@ -36,9 +36,9 @@ class Fido2:
 		# to prevent continous reloading which will slow
 		# down moving the cursor in the menu
 		if not cls._loaded or reload:
-			ret = ""
+			ret: Optional[str] = None
 			try:
-				ret = Optional[str] = SysCommand(f"systemd-cryptenroll --fido2-device=list").decode('UTF-8')
+				ret = SysCommand("systemd-cryptenroll --fido2-device=list").decode('UTF-8')
 			except:
 				error('fido2 support is most likely not installed')
 			if not ret: