gopls/internal/test/marker: update regression test issue68918.txt

The fix for golang/go#69092 produces an extra error message in Go 1.24.
Ignore it.

Updates golang/go#68918.
Updates golang/go#69092.

Change-Id: I41ecff6fe916a04ed943e29ad10184d340ef84d5
Reviewed-on: https://go-review.googlesource.com/c/tools/+/617475
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

gopls/internal/test/marker/testdata/highlight/issue68918.txt

@@ -1,6 +1,12 @@
 Regression test for https://github.com/golang/go/issues/68918:
 crash due to missing type information in CompositeLit.
 
+The corresponding go/types fix in Go 1.24 introduces a
+new error message, hence the -ignore_extra_diags flag.
+
+-- flags --
+-ignore_extra_diags
+
 -- a.go --
 package a