first_stage_test: Format code using ruff

Signed-off-by: Marc Hartmayer <[email protected]>

Author: mhartmay

tests/first_stage_test.py

@@ -1,11 +1,11 @@
 import subprocess
 
+import testlib
+
 import mitogen.core
 import mitogen.parent
 from mitogen.core import b
 
-import testlib
-
 
 class CommandLineTest(testlib.RouterMixin, testlib.TestCase):
     # Ensure this version of Python produces a command line that is sufficient
@@ -35,15 +35,17 @@ def test_valid_syntax(self):
 
         fp = open("/dev/zero", "r")
         try:
-            proc = subprocess.Popen(args,
+            proc = subprocess.Popen(
+                args,
                 stdin=fp,
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
             )
             stdout, stderr = proc.communicate()
             self.assertEqual(0, proc.returncode)
-            self.assertEqual(stdout,
-                mitogen.parent.BootstrapProtocol.EC0_MARKER+b('\n'))
+            self.assertEqual(
+                stdout, mitogen.parent.BootstrapProtocol.EC0_MARKER + b("\n")
+            )
             self.assertIn(
                 b("Error -3 while decompressing data"),  # Unknown compression method
                 stderr,