cli/command/container: Simplify with slices.Contains

Signed-off-by: Paweł Gronowski <[email protected]>

Author: vvoland

cli/command/container/opts.go

@@ -3,6 +3,7 @@
 package container
 
 import (
+	"slices"
 	"bytes"
 	"encoding/json"
 	"errors"
@@ -1132,11 +1133,9 @@ func validateLinuxPath(val string, validator func(string) bool) (string, error)
 // validateAttach validates that the specified string is a valid attach option.
 func validateAttach(val string) (string, error) {
 	s := strings.ToLower(val)
-	for _, str := range []string{"stdin", "stdout", "stderr"} {
-		if s == str {
+	if slices.Contains([]string{"stdin", "stdout", "stderr"}, s) {
 			return s, nil
 		}
-	}
 	return val, errors.New("valid streams are STDIN, STDOUT and STDERR")
 }