Added warning message in changing passwords in Docker and Kubernetes

[davidcr01]

Description

Closes: #7319
The aim of this PR is to add a warning message in the Docker and Kubernetes change password documentation:

• https://documentation.wazuh.com/current/deployment-options/docker/wazuh-container.html#change-the-password-of-wazuh-users
• https://documentation.wazuh.com/current/deployment-options/deploying-with-kubernetes/kubernetes-deployment.html#change-the-password-of-wazuh-users

The message informs the user not to specify the & and the $ characters in the new passwords, as they can break the deployment.

The final result is the following:

[javimed]

Checks

Docs building

• Compiles without warnings.

Code formatting and web optimization

• Uses three spaces indentation.
• Adds or updates meta descriptions accordingly.
• Updates the redirects.js script if necessary (check this guide).

Writing style

• Uses present tense, active voice, and semi-formal registry.
• Uses short, simple sentences.
• Uses bold for user interface elements, italics for key terms or emphasis, and code font for Bash commands, file names, REST paths, and code.