Refactor tests (#26464)

1. Give the global variable clear names
2. Use generic parameter for `onGiteaRun`

tests/integration/create_no_session_test.go

@@ -56,7 +56,7 @@ func TestSessionFileCreation(t *testing.T) {
 	oldSessionConfig := setting.SessionConfig.ProviderConfig
 	defer func() {
 		setting.SessionConfig.ProviderConfig = oldSessionConfig
-		c = routers.NormalRoutes()
+		testWebRoutes = routers.NormalRoutes()
 	}()
 
 	var config session.Options
@@ -75,7 +75,7 @@ func TestSessionFileCreation(t *testing.T) {
 
 	setting.SessionConfig.ProviderConfig = string(newConfigBytes)
 
-	c = routers.NormalRoutes()
+	testWebRoutes = routers.NormalRoutes()
 
 	t.Run("NoSessionOnViewIssue", func(t *testing.T) {
 		defer tests.PrintCurrentTest(t)()