Support new stage Alpha 1 for 4.9.0 in wazuh-docker repository

[juliamagan]

Description

This issue attempts to support a new stage Alpha 1 for 4.9.0 in the wazuh-docker repository.

Tasks

• [x] Ensure changelog is updated for 4.9.0 (if applicable).
• [x] Bump revision for branch 4.9.0 on wazuh-docker repository.
• [x] Change docker image tag in docker-compose to tag v4.9.0-alpha1 in branch 4.9.0
• [x] Create tag v4.9.0-alpha1 from branch 4.9.0 on wazuh-docker repository.
• [x] Create and publish a pre-release: https://github.com/wazuh/wazuh-docker/releases/tag/v4.9.0-alpha1.
• [x] Change docker image tag in docker-compose back to 4.9.0 in branch 4.9.0

[CarlosALgit]

LGTM!