Prepare 5.0.0 (#1123)

* Bump version to 5.0.0-a1.

* Drop support for ansible-core 2.15 and 2.16.

* Remove Python 2 and early Python 3 compatibility.

plugins/modules/docker_stack.py

@@ -5,8 +5,7 @@
 # GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-from __future__ import (absolute_import, division, print_function)
-__metaclass__ = type
+from __future__ import annotations
 
 
 DOCUMENTATION = r"""
@@ -161,7 +160,6 @@ import os
 import tempfile
 import traceback
 
-from ansible_collections.community.docker.plugins.module_utils._six import string_types
 from time import sleep
 
 from ansible.module_utils.common.text.converters import to_native
@@ -280,7 +278,7 @@ def main():
                     with os.fdopen(compose_file_fd, 'w') as stack_file:
                         compose_files.append(compose_file)
                         stack_file.write(yaml_dump(compose_def))
-                elif isinstance(compose_def, string_types):
+                elif isinstance(compose_def, str):
                     compose_files.append(compose_def)
                 else:
                     client.fail("compose element '%s' must be a string or a dictionary" % compose_def)