extension/test/gopls: allow more time for testify tests

gopls needs to load stretchr and its dependencies to analyze
stretchrTestSuite test package, used for the recently added
"Code lenses with stretchr/testify/suite" test.
Windows GH workflow is not fast enough to complete module
and package loads. Allow more time.

Fixes #3172

Change-Id: Iac304793948ce8ff3d0ba415868e239668cbbcf7
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/563695
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Commit-Queue: Hyang-Ah Hana Kim <hyangah@gmail.com>

Author: hyangah

extension/test/gopls/codelens.test.ts

@@ -229,6 +229,10 @@ suite('Code lenses for testing and benchmarking', function () {
 });
 
 suite('Code lenses with stretchr/testify/suite', function () {
+	if (process.platform === 'win32') {
+		this.timeout(20000); // Gopls on windows needs more time to load required modules.
+	}
+
 	const ctx = MockExtensionContext.new();
 
 	const testdataDir = path.join(__dirname, '..', '..', '..', 'test', 'testdata', 'stretchrTestSuite');