Operator and metrics-exporter images use EOL Debian 11

Both images for `clickhouse-operator` as well as `metrics-exporter` are based on `gcr.io/distroless/static-debian11` which has been deprecated by distroless since 2024-06-01 (https://github.com/GoogleContainerTools/distroless/blob/7115f63370d35ef6134)

Both images should be updated to Debian 13, which is the current stable version.