imgtool: fix dependency on click version

# See the License for the specific language governing permissions and

# limitations under the License.

from importlib import metadata

import pytest

from click.testing import CliRunner

from imgtool.main import imgtool

from imgtool import imgtool_version

from packaging.version import Version

# all available imgtool commands

COMMANDS = [

    # by default help should be also produced

    result_empty = runner.invoke(imgtool)

    assert result_empty.exit_code == 0

    # return value without arguments differs based on click version

    expected_exit_code = 2 if Version(metadata.version("click")) >= Version("8.2.0") else 0

    assert result_empty.exit_code == expected_exit_code

    assert result_empty.output == result_short.output