Format the unused-argument fixture as master's printer does

Master's printer now puts a blank line around multi-line items (#8961), so the
format check failed on this fixture after the rebase. Its error snapshot moves
by one line.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Kbf3gLpf7RN1MiRcubPgRn
Signed-off-by: Christoph Knittel <ck@cca.io>

Author: cknitt

tests/build_tests/super_errors/expected/unused_argument_object_method.res.expected

@@ -1,36 +1,36 @@
 
   Warning number 20
-  /.../fixtures/unused_argument_object_method.res:28:51
+  /.../fixtures/unused_argument_object_method.res:29:51
 
-  26 │ 
-  27 │ // A function that never returns ignores its arguments: warning 20.
-  28 │ let ignored = () => throw(Failure("unreachable"))(1)
-  29 │ 
-  30 │ // A field read that cannot return ignores its arguments: warning 20.
+  27 │ 
+  28 │ // A function that never returns ignores its arguments: warning 20.
+  29 │ let ignored = () => throw(Failure("unreachable"))(1)
+  30 │ 
+  31 │ // A field read that cannot return ignores its arguments: warning 20.
 
   this argument will not be used by the function.
 
 
   Warning number 20
-  /.../fixtures/unused_argument_object_method.res:31:62-77
+  /.../fixtures/unused_argument_object_method.res:32:62-77
 
-  29 │ 
-  30 │ // A field read that cannot return ignores its arguments: warning 20.
-  31 │ let fromLiteral = () => ({"m": throw(Failure("boom"))})["m"](Console.lo
+  30 │ 
+  31 │ // A field read that cannot return ignores its arguments: warning 20.
+  32 │ let fromLiteral = () => ({"m": throw(Failure("boom"))})["m"](Console.lo
      │ g("a"))
-  32 │ let fromThrow = () => throw(Failure("boom"))["m"](Console.log("b"))
-  33 │ 
+  33 │ let fromThrow = () => throw(Failure("boom"))["m"](Console.log("b"))
+  34 │ 
 
   this argument will not be used by the function.
 
 
   Warning number 20
-  /.../fixtures/unused_argument_object_method.res:32:51-66
+  /.../fixtures/unused_argument_object_method.res:33:51-66
 
-  30 │ // A field read that cannot return ignores its arguments: warning 20.
-  31 │ let fromLiteral = () => ({"m": throw(Failure("boom"))})["m"](Console.lo
+  31 │ // A field read that cannot return ignores its arguments: warning 20.
+  32 │ let fromLiteral = () => ({"m": throw(Failure("boom"))})["m"](Console.lo
      │ g("a"))
-  32 │ let fromThrow = () => throw(Failure("boom"))["m"](Console.log("b"))
-  33 │ 
+  33 │ let fromThrow = () => throw(Failure("boom"))["m"](Console.log("b"))
+  34 │ 
 
   this argument will not be used by the function.

tests/build_tests/super_errors/fixtures/unused_argument_object_method.res

@@ -17,6 +17,7 @@ let nested = clipboardData("e")["m"](clipboardData("f")["n"]("y"))
 let retained = clipboardData("e")
 let first = retained["m"]
 let second = retained["m"]("used")
+
 let readElsewhere = () => {
   let o = clipboardData("e")
   let get = () => o["m"]