Update go-viper to v2 causes issues

[codeboten]

Spent some time on this one. There's some messages that end up reporting an additional empty error:

expected: "decoding failed due to the following error(s):\n\nerror decoding 'err': never works"
actual  : "decoding failed due to the following error(s):\n\nerror decoding '': decoding failed due to the following error(s):\n\nerror decoding 'err': never works"

It's unclear to me why

Originally posted by @codeboten in https://github.com/open-telemetry/opentelemetry-collector/issues/10300#issuecomment-2160771395