fix(psiphon): increase the maximum runtime to 300s (ooni#596)

See: ooni/probe#1856.

This diff will need to be backported to release/3.11.

internal/engine/experiment/psiphon/psiphon.go

@@ -16,7 +16,7 @@ import (
 
 const (
 	testName    = "psiphon"
-	testVersion = "0.5.0"
+	testVersion = "0.5.1"
 )
 
 // Config contains the experiment's configuration.
@@ -70,7 +70,7 @@ func (m *Measurer) Run(
 	ctx context.Context, sess model.ExperimentSession,
 	measurement *model.Measurement, callbacks model.ExperimentCallbacks,
 ) error {
-	const maxruntime = 60
+	const maxruntime = 300
 	ctx, cancel := context.WithTimeout(ctx, maxruntime*time.Second)
 	var (
 		wg     sync.WaitGroup

internal/engine/experiment/psiphon/psiphon_test.go

@@ -23,7 +23,7 @@ func TestNewExperimentMeasurer(t *testing.T) {
 	if measurer.ExperimentName() != "psiphon" {
 		t.Fatal("unexpected name")
 	}
-	if measurer.ExperimentVersion() != "0.5.0" {
+	if measurer.ExperimentVersion() != "0.5.1" {
 		t.Fatal("unexpected version")
 	}
 }