ScyllaDB release: version 1.6.3

ScyllaDB 1.6.3 is a bugfix release for the ScyllaDB 1.6 stable branch, focusing on backward compatibility and supporting rolling upgrades, with essential updates for users transitioning from version 1.5.x. Key fixes include renaming duplicate storage_proxy metrics, resolving commitlog replay errors after unexpected restarts, opening the Prometheus port by default in the Docker image, and preventing crashes in the golang driver, gocql, when certain logging features are enabled. Additionally, it addresses issues with node-to-node SSL logging messages and startup failures of the ScyllaDB service after setup and server restarts, ensuring a smoother experience for users and administrators.