update viper

[kamilsk]

• https://github.com/spf13/viper/releases/tag/v1.9.0
• https://github.com/spf13/viper/releases/tag/v1.10.0
• https://github.com/spf13/viper/releases/tag/v1.10.1
• https://github.com/spf13/viper/releases/tag/v1.11.0