[chore]: Bump github.com/spf13/viper from 1.19.0 to 1.20.0

Bumps [github.com/spf13/viper](https://github.com/spf13/viper) from 1.19.0 to 1.20.0.
- [Release notes](https://github.com/spf13/viper/releases)
- [Commits](https://github.com/spf13/viper/compare/v1.19.0...v1.20.0)

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

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

vendor/github.com/spf13/viper/util.go

@@ -12,13 +12,13 @@ package viper
 
 import (
 	"fmt"
+	"log/slog"
 	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"unicode"
 
-	slog "github.com/sagikazarmark/slog-shim"
 	"github.com/spf13/cast"
 )
 
@@ -128,15 +128,6 @@ func absPathify(logger *slog.Logger, inPath string) string {
 	return ""
 }
 
-func stringInSlice(a string, list []string) bool {
-	for _, b := range list {
-		if b == a {
-			return true
-		}
-	}
-	return false
-}
-
 func userHomeDir() string {
 	if runtime.GOOS == "windows" {
 		home := os.Getenv("HOMEDRIVE") + os.Getenv("HOMEPATH")