extension/tools/release: skip validation for dir in zip

TestBuildVSCGO failure causing LUCI post submit failure.

For #3533

Change-Id: I11fe1154293ff91b7e06897f7f572f24a9ccc5eb
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/642479
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
kokoro-CI: kokoro <noreply+kokoro@google.com>
Commit-Queue: Hongxiang Jiang <hxjiang@golang.org>

extension/tools/release/release_test.go

@@ -137,6 +137,12 @@ func TestBuildVSCGO(t *testing.T) {
 		want[platform.goos+"_"+platform.goarch] = true
 	}
 	for _, f := range zipReader.File {
+		// CL 578415 modifies the behavior of archive/zip.Writer.AddFS regarding
+		// writing headers to zip files.
+		// See golang/go#66831 for details.
+		if f.FileInfo().IsDir() {
+			continue
+		}
 		dirname := path.Base(path.Dir(f.Name))
 		if !want[dirname] {
 			t.Errorf("unexpected file in zip: %v", f.Name)