test/gopls/survey.test: removed the unread variable

Change-Id: Ib576ad8b7e85368f6e28fbc4846a10ec3da20f7e
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/400361
Reviewed-by: Jamal Carvalho <jamal@golang.org>
diff --git a/test/gopls/survey.test.ts b/test/gopls/survey.test.ts
index 160e682..51f1a20 100644
--- a/test/gopls/survey.test.ts
+++ b/test/gopls/survey.test.ts
@@ -221,7 +221,7 @@
 			const stub = sandbox.stub(vscode.window, 'showInformationMessage').resolves({ title: choice });
 			const getGoplsOptOutConfigStub = sandbox.stub(goLanguageServer, 'getGoplsOptOutConfig').returns(testConfig);
 			const flushGoplsOptOutConfigStub = sandbox.stub(goLanguageServer, 'flushGoplsOptOutConfig');
-			const openWindowStub = sandbox.stub(vscode.env, 'openExternal').resolves(true);
+			sandbox.stub(vscode.env, 'openExternal').resolves(true);
 
 			await goLanguageServer.promptAboutGoplsOptOut();
 			assert.strictEqual(stub.callCount, wantCount, 'unexpected call count');