gopls/internal/test/marker: ignore diags in fixedbugs/issue59944.txt

go/types now (correctly) produces a diagnostic for this code.

For golang/go#59944

Change-Id: I858acbf4199171f6e6c98eb1286d037e89462018
Reviewed-on: https://go-review.googlesource.com/c/tools/+/630117
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>

Author: findleyr

gopls/internal/test/marker/testdata/fixedbugs/issue59944.txt

@@ -4,8 +4,12 @@ the methodset of its receiver type.
 
 Adapted from the code in question from the issue.
 
+The flag -ignore_extra_diags is included, as this bug was fixed in Go 1.24, so
+that now the code below may produce a diagnostic.
+
 -- flags --
 -cgo
+-ignore_extra_diags
 
 -- go.mod --
 module example.com