Test failing on extra fields parsing

[alexbozhenko]

# go run ./cmd/golangci-lint/ run -v
INFO golangci-lint has version (devel) built with go1.23.4 from (unknown, modified: ?, mod sum: "") on (unknown)
INFO [config_reader] Config search paths: [./ /home/alex/code/golangci-lint /home/alex/code /home/alex /home /]
INFO [config_reader] Used config file .golangci.yml
Error: can't load config: can't unmarshal config by viper (flags, file): 2 error(s) decoding:

* '' has invalid keys: linterss
* 'output.formats[0]' expected a map, got 'string'
Failed executing command with error: can't load config: can't unmarshal config by viper (flags, file): 2 error(s) decoding:

* '' has invalid keys: linterss
* 'output.formats[0]' expected a map, got 'string'
exit status 3

[❌ ERROR]

Fixes: #5313