[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

tests/transports/test_ssh.py

@@ -81,7 +81,7 @@ def list_open_fds():
         return process.open_files()
 
     open_fds = list_open_fds()
-    msg = f"Number of open file descriptor: {len(open_fds)}\n\n\n {open_fds}"
+    msg = f'Number of open file descriptor: {len(open_fds)}\n\n\n {open_fds}'
     raise ValueError(msg)
 
     try: