Add playbook and kayobe automation breaking change info

Added more detail about two breaking changes on Epoxy.
1. Any playbook reference other than symlinks can break with new
   subdirectories of playbooks.
2. Kayobe Automation image needs to be rebuilt with Python 3.12.

Author: seunghun1ee

doc/source/operations/upgrading-openstack.rst

@@ -132,7 +132,7 @@ For example:
       enabled: "{{ seed_pulp_container_enabled | bool }}"
 
 Ansible playbook subdirectories
---------------------------------------
+-------------------------------
 
 The playbooks under ``etc/kayobe/ansible`` have been subdivided into different
 categories to make them easier to navigate. This change may result in merge
@@ -147,6 +147,10 @@ To mitigate the impact of these changes, two scripts have been added:
 * ``tools/magic-symlink-fix.sh`` - Uses the previous script to attempt to fix
   any broken symlinks in the kayobe configuration.
 
+If playbooks are referenced in different methods other than symlinks, they'll
+need to manually resolved by operators. (e.g. Shell scripts running playbooks
+with file paths, ``import_playbook`` command in custom playbooks)
+
 Known issues
 ============
 
@@ -370,6 +374,17 @@ You can find more information from the :ref:`beokay` documentation.
    For Rocky Linux 9, ``beokay create`` must be used with the ``--python python3.12``
    option to specify Beokay to use Python 3.12 as it is not the default.
 
+For CI, Kayobe Automation image also needs to be rebuilt with Python 3.12.
+When building Kayobe Automation image, use argument ``USE_PYTHON_312``.
+
+For example:
+
+.. code:: bash
+
+   docker build $KAYOBE_CONFIG_PATH/../../.automation/docker/kayobe/Dockerfile \
+   -t kayobe:latest \
+   -e USE_PYTHON_312=true
+
 Preparation
 ===========