bump spilo to 16-3.3, drop support for pg11 (#2706)

README.md

charts/postgres-operator/crds/operatorconfigurations.yaml

charts/postgres-operator/crds/postgresqls.yaml

charts/postgres-operator/values.yaml

manifests/complete-postgres-manifest.yaml

manifests/configmap.yaml

manifests/operatorconfiguration.crd.yaml

manifests/postgresql-operator-default-configuration.yaml

manifests/postgresql.crd.yaml

pkg/apis/acid.zalan.do/v1/crds.go

pkg/cluster/majorversionupgrade.go

pkg/controller/operator_config.go

pkg/util/config/config.go

ui/operator_ui/spiloutils.py