refactor(errs): migrate from gperr.Error to standard Go error interface

This is a large-scale refactoring across the codebase that replaces the custom
`gperr.Error` type with Go's standard `error` interface. The changes include:

- Replacing `gperr.Error` return types with `error` in function signatures
- Using `errors.New()` and `fmt.Errorf()` instead of `gperr.New()` and `gperr.Errorf()`
- Using `%w` format verb for error wrapping instead of `.With()` method
- Replacing `gperr.Subject()` calls with `gperr.PrependSubject()`
- Converting error logging from `gperr.Log*()` functions to zerolog's `.Err().Msg()` pattern
- Update NewLogger to handle multiline error message
- Updating `goutils` submodule to latest commit

This refactoring aligns with Go idioms and removes the dependency on
custom error handling abstractions in favor of standard library patterns.

internal/maxmind/types/config.go

@@ -3,7 +3,6 @@ package maxmind
 import (
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
-	gperr "github.com/yusing/goutils/errs"
 	strutils "github.com/yusing/goutils/strings"
 )
 
@@ -21,7 +20,7 @@ const (
 	MaxMindGeoIP2  DatabaseType = "geoip2"
 )
 
-func (cfg *Config) Validate() gperr.Error {
+func (cfg *Config) Validate() error {
 	if cfg.Database == "" {
 		cfg.Database = MaxMindGeoLite
 	}