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

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

src/pylibsshext/channel.pyx

@@ -20,11 +20,13 @@ import time
 from io import BytesIO
 
 from cpython.bytes cimport PyBytes_AS_STRING
-from cpython.mem cimport PyMem_Malloc, PyMem_Free
+from cpython.mem cimport PyMem_Free, PyMem_Malloc
 from libc.string cimport memset
 
 from pylibsshext.errors cimport LibsshChannelException
+
 from pylibsshext.errors import LibsshChannelReadFailure
+
 from pylibsshext.session cimport get_libssh_session
 
 from subprocess import CompletedProcess