chore: fix a warning from Ansible about Python interpeter discovery by explicitly specifying it

The warning was:
[DEPRECATION WARNING]: Distribution Ubuntu 16.04 on host my-stamps.ru should use /usr/bin/python3,
but is using /usr/bin/python for backward compatibility with prior Ansible releases. A future Ansible
release will default to using the discovered platform python for this host. See
https://docs.ansible.com/ansible/2.9/reference_appendices/interpreter_discovery.html for more information.
This feature will be removed in version 2.12. Deprecation warnings can be disabled by setting
deprecation_warnings=False in ansible.cfg.

Fix #1192

Author: php-coder

src/main/scripts/ci/ansible/mystamps.inventory

@@ -1,3 +1,10 @@
 # Ansible inventory file
 # See: https://docs.ansible.com/ansible/2.9/user_guide/intro_inventory.html
+
+[prod]
 my-stamps.ru
+
+[all:vars]
+# https://docs.ansible.com/ansible/2.9/reference_appendices/python_3_support.html#using-python-3-on-the-managed-machines-with-commands-and-playbooks
+# https://docs.ansible.com/ansible/2.9/reference_appendices/interpreter_discovery.html
+ansible_python_interpreter=/usr/bin/python3