internal: temporarily disable tests so we can land CL 410955

For golang/go#53279.

Change-Id: I3e0a502f8f0789ff9920af504ea8c86812bf49a1
Reviewed-on: https://go-review.googlesource.com/c/tools/+/410956
Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

normalize_test.go

@@ -17,6 +17,8 @@ import (
 )
 
 func TestStructuralTerms(t *testing.T) {
+	t.Skip() // re-enable once CL 410955 has landed
+
 	if !Enabled {
 		t.Skip("typeparams are not enabled")
 	}