v3_5_experimental: add new error

Author: yasminvalim

config/shared/errors/errors.go

@@ -85,6 +85,7 @@ var (
 	ErrInvalidProxy              = errors.New("proxies must be http(s)")
 	ErrInsecureProxy             = errors.New("insecure plaintext HTTP proxy specified for HTTPS resources")
 	ErrPathConflictsSystemd      = errors.New("path conflicts with systemd unit or dropin")
+	ErrPathConflictsParentDir    = errors.New("path conflicts with parent directory of another file, link, or directory")
 
 	// Systemd section errors
 	ErrInvalidSystemdExt       = errors.New("invalid systemd unit extension")