Add support for RUN --mount=type=secret env

[fox91]

Already reported by hadolint/hadolint/issues/1039 but need to be solved here:

language-docker/src/Language/Docker/Parser/Run.hs

Lines 158 to 164 in dba56a7

	secretMount :: [RunMountArg] -> Parser SecretOpts
	secretMount args =
	case validArgs "secret" allowed required args of
	Left e -> customError e
	Right as -> return $ foldr secretOpts def as
	where
	allowed = Set.fromList ["target", "id", "required", "source", "mode", "uid", "gid"]

Example:

# syntax=docker/dockerfile:1.10

FROM node:20

RUN --mount=type=secret,id=ENV_VAR,env=ENV_VAR echo "ENV_VAR=$ENV_VAR" > /tmp/env_var

Exit with error:

Dockerfile.test:6:36 unexpected "env=ENV_VAR ec" expecting "gid=", "id=", "mode=", "required", "required=False", "required=True", "required=false", "required=true", "uid=", source=, or target=