Add comprehensive tests for action precondition
This patch adds a new test suite TestExecuteSkippedActions that
validates the precondition checking logic for various Watcher actions.
These tests ensure that actions are properly skipped when preconditions
are not met (resulting in SKIPPED state with SUCCEEDED action plan)
or fail appropriately when invalid parameters are provided
(resulting in FAILED state for both action and action plan).
The test suite covers 14 scenarios across 5 action types:

https://docs.openstack.org/watcher/latest/actions/migrate.html
https://docs.openstack.org/watcher/latest/actions/change_nova_service_state.html
https://docs.openstack.org/watcher/latest/actions/resize.html
https://docs.openstack.org/watcher/latest/actions/stop.html
https://docs.openstack.org/watcher/latest/actions/volume_migration.html

All tests follow a consistent pattern using a helper method
execute_actions_and_validate_states() that:

Creates audit templates and audits with custom actions
Optionally executes pre-execution hooks (e.g., deleting resources)
Executes action plans and waits for completion
Validates expected action states and action plan final state
Returns action details for additional verification

As this feature is not backported, skipped actions have to be excluded
from 2025* and 2024* branches on watcher project zuul jobs definition
Change-Id: Ifaf9ed0b00d9a38031a824e0a11aa91b04e06ec4
Assisted-By: Claude
Signed-off-by: morenod dsanzmor@redhat.com