fix: Use dynamic controller-runtime version in doc generator

Replace hardcoded controller-runtime version in hack/docs/internal/cronjob-tutorial/generate_cronjob.go with a reference to the ControllerRuntimeVersion constant from the scaffolding package.

This prevents the docs generation from breaking when the controller-runtime version is updated in the scaffolding logic, ensuring that `make generate-docs` remains stable across version bumps.

Update hack/docs/internal/cronjob-tutorial/generate_cronjob.go

Co-authored-by: Saan <94980910+sbin64@users.noreply.github.com>

Update hack/docs/internal/cronjob-tutorial/generate_cronjob.go

Co-authored-by: Kersten Burkhardt <kerstenk@gmail.com>

Author: p-shah256

hack/docs/internal/cronjob-tutorial/generate_cronjob.go

@@ -17,13 +17,15 @@ limitations under the License.
 package cronjob
 
 import (
+	"fmt"
 	"os/exec"
 	"path/filepath"
 
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/afero"
 	hackutils "sigs.k8s.io/kubebuilder/v4/hack/docs/utils"
 	pluginutil "sigs.k8s.io/kubebuilder/v4/pkg/plugin/util"
+	"sigs.k8s.io/kubebuilder/v4/pkg/plugins/golang/v4/scaffolds"
 	"sigs.k8s.io/kubebuilder/v4/test/e2e/utils"
 )
 
@@ -288,7 +290,8 @@ func (sp *Sample) updateController() {
 
 	err = pluginutil.InsertCode(
 		filepath.Join(sp.ctx.Dir, "internal/controller/cronjob_controller.go"),
-		`// - https://pkg.go.dev/sigs.k8s.io/controller-runtime@v0.20.4/pkg/reconcile`, skipGoCycloLint)
+		fmt.Sprintf(`// - https://pkg.go.dev/sigs.k8s.io/controller-runtime@%s/pkg/reconcile`,
+			scaffolds.ControllerRuntimeVersion), skipGoCycloLint)
 	hackutils.CheckError("fixing cronjob_controller.go", err)
 
 	err = pluginutil.ReplaceInFile(