test/integration: run parallel tests concurrently with serial tests

Signed-off-by: Monis Khan <mok@vmware.com>

test/integration/formposthtml_test.go

@@ -24,7 +24,10 @@ import (
 	"go.pinniped.dev/test/testlib/browsertest"
 )
 
-func TestFormPostHTML(t *testing.T) {
+// safe to run in parallel with serial tests since it only interacts with a test local server, see main_test.go.
+func TestFormPostHTML_Parallel(t *testing.T) {
+	_ = testlib.IntegrationEnv(t)
+
 	// Run a mock callback handler, simulating the one running in the CLI.
 	callbackURL, expectCallback := formpostCallbackServer(t)