Update github.com/stretchr/testify to enable suite usage

[thatgim]

Hi!

I just noticed I can't use github.com/stretchr/testify/suite with httpexpect because in v1.5.0 Suite.T() returns a custom wrapper type TestingT. https://pkg.go.dev/github.com/stretchr/[email protected]/suite#Suite.T In the latest version this is fixed/better because it just returns a regular *testing.T. https://pkg.go.dev/github.com/stretchr/[email protected]/suite#Suite.T