Bump github.com/stretchr/testify from 1.8.3 to 1.8.4 in /backend

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](stretchr/testify@v1.8.3...v1.8.4)

---
updated-dependencies:
- dependency-name: github.com/stretchr/testify
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

backend/go.mod

@@ -21,7 +21,7 @@ require (
 	github.com/mmcdole/gofeed v1.2.1
 	github.com/spf13/cobra v1.7.0
 	github.com/spf13/viper v1.16.0
-	github.com/stretchr/testify v1.8.3
+	github.com/stretchr/testify v1.8.4
 	github.com/swaggo/files v1.0.1
 	github.com/swaggo/gin-swagger v1.6.0
 	github.com/swaggo/swag v1.8.12

backend/go.sum

@@ -1361,8 +1361,9 @@ github.com/stretchr/testify v1.7.5/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-github.com/stretchr/testify v1.8.3 h1:RP3t2pwF7cMEbC1dqtB6poj3niw/9gnV4Cjg5oW5gtY=
 github.com/stretchr/testify v1.8.3/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/subosito/gotenv v1.4.2 h1:X1TuBLAMDFbaTAChgCBLu3DU3UPyELpnF2jjJ2cz/S8=
 github.com/subosito/gotenv v1.4.2/go.mod h1:ayKnFf/c6rvx/2iiLrJUk1e6plDbT3edrFNGqEflhK0=
 github.com/swaggo/files v1.0.1 h1:J1bVJ4XHZNq0I46UU90611i9/YzdrF7x92oX1ig5IdE=