Format Python sender input test

Wrap the sender-builder assertion in the Python unit test the\nway treefmt expects.\n\nThe PR was failing the formatting job on this one call site even\nthough the branch logic was already correct. Keeping the file in the\nformatter's preferred layout avoids a no-op CI failure on #1432.

Author: chavic

payjoin-ffi/python/test/test_payjoin_unit_test.py

@@ -247,9 +247,9 @@ def test_sender_builder_exposes_invalid_original_input_index(self):
         uri = receiver.pj_uri()
 
         with self.assertRaises(payjoin.SenderInputError.Build) as ctx:
-            payjoin.SenderBuilder(payjoin.invalid_original_input_psbt(), uri).build_non_incentivizing(
-                1000
-            )
+            payjoin.SenderBuilder(
+                payjoin.invalid_original_input_psbt(), uri
+            ).build_non_incentivizing(1000)
 
         error = ctx.exception[0]
         self.assertEqual(error.invalid_original_input_index(), 0)