Build(deps): bump github.com/stretchr/testify from 1.8.3 to 1.8.4

Bumps [github.com/stretchr/testify](https://github.com/stretchr/testify) from 1.8.3 to 1.8.4.
- [Release notes](https://github.com/stretchr/testify/releases)
- [Commits](https://github.com/stretchr/testify/compare/v1.8.3...v1.8.4)

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/alecthomas/kong v0.7.1
 	github.com/apex/log v1.9.0
 	github.com/aws/aws-sdk-go v1.44.270
-	github.com/stretchr/testify v1.8.3
+	github.com/stretchr/testify v1.8.4
 	gitlab.com/unboundsoftware/apex-mocks v0.2.0
 )