Fix handling of trailing target comment (#9051)

crates/ruff_python_formatter/tests/snapshots/format@statement__assign.py.snap

@@ -73,6 +73,15 @@ def main() -> None:
                 db_request.POST["name"]
             )
         )[0]
+
+
+c = b[dddddd, aaaaaa] =  (
+    a[
+        aaaaaaa,
+        bbbbbbbbbbbbbbbbbbb
+    ]
+    # comment
+) = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
 ```
 
 ## Output
@@ -151,6 +160,12 @@ def main() -> None:
                 db_request.POST["name"]
             )
         )[0]
+
+
+c = b[dddddd, aaaaaa] = (
+    a[aaaaaaa, bbbbbbbbbbbbbbbbbbb]
+    # comment
+) = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
 ```