Attributes – Update the {MaistraVersion} variable in the common-attributes file

The following will be automatically updated for the new release:

• Updates references to the ServiceMeshControlPlane version in text.
• Updates references to the ServiceMeshControlPlane spec.version field in code examples.
• Updates the SMCP version in the configuration reference topic for spec.version.
• Updates the URLs for the bookinfo sample files.
• Updates the URL for sample certificate files in the Certificate Management module.