Making ImagePullPolicy in NMC optional

Currently ImagePullPolicy has a kubebuilder instruction for default
value, which automatically makes it a required field. In previous
version, this field was optional, meaning: when upgrading KMM operator,
the upgrade will fail , since NMC object will be missing the required
field
This commit keep the default value, but makes this field optional, in
order to solve the upgrade issue

api/v1beta1/nodemodulesconfig_types.go

@@ -25,6 +25,7 @@ type ModuleConfig struct {
 	KernelVersion  string `json:"kernelVersion"`
 	ContainerImage string `json:"containerImage"`
 	// +kubebuilder:default=IfNotPresent
+	//+optional
 	ImagePullPolicy v1.PullPolicy `json:"imagePullPolicy"`
 	// When InsecurePull is true, the container image can be pulled without TLS.
 	InsecurePull bool `json:"insecurePull"`

config/crd/bases/kmm.sigs.x-k8s.io_nodemodulesconfigs.yaml

@@ -194,7 +194,6 @@ spec:
                           type: array
                       required:
                       - containerImage
-                      - imagePullPolicy
                       - insecurePull
                       - kernelVersion
                       - modprobe
@@ -384,7 +383,6 @@ spec:
                           type: array
                       required:
                       - containerImage
-                      - imagePullPolicy
                       - insecurePull
                       - kernelVersion
                       - modprobe