fix operatorconfigurations CRD: render sidecars as array

configuration.sidecars was annotated with kubebuilder:validation:Type=object
while SidecarContainers is a []v1.Container, so the generated schema rejected
every list value and global sidecars could not be configured at all.

Drop the hand-written Schemaless/Type=object markers and let controller-gen
derive the schema from the Go type, the same way spec.initContainers is
already handled in the Postgresql CRD. The field now renders as type: array
with a full Container schema for its items.

Fixes #3159

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

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

@@ -430,9 +430,7 @@ type OperatorConfigurationData struct {
 	// +kubebuilder:default=true
 	ShmVolume     *bool             `json:"enable_shm_volume,omitempty"`
 	SidecarImages map[string]string `json:"sidecar_docker_images,omitempty"` // deprecated in favour of SidecarContainers
-	// +kubebuilder:validation:XPreserveUnknownFields
-	// +kubebuilder:validation:Type=object
-	// +kubebuilder:validation:Schemaless
+	// +nullable
 	SidecarContainers []v1.Container `json:"sidecars,omitempty"`
 	// +optional
 	PostgresUsersConfiguration PostgresUsersConfiguration `json:"users"`