build(deps): bump github.com/spf13/pflag in /frontend

Bumps [github.com/spf13/pflag](https://github.com/spf13/pflag) from 1.0.5 to 1.0.6.
- [Release notes](https://github.com/spf13/pflag/releases)
- [Commits](https://github.com/spf13/pflag/compare/v1.0.5...v1.0.6)

---
updated-dependencies:
- dependency-name: github.com/spf13/pflag
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

frontend/go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/gorilla/handlers v1.5.2
 	github.com/jarcoal/httpmock v1.3.1
 	github.com/magiconair/properties v1.8.9
-	github.com/spf13/pflag v1.0.5
+	github.com/spf13/pflag v1.0.6
 	github.com/spf13/viper v1.19.0
 )