Dashboard: Allow disabling dashboard grid lazy loading (#89280)

* Schema update

* Dashboard: Allow opting out from dashboard panels lazy loading

* Locale

* Lint fix

* Snaps fix

pkg/kinds/dashboard/dashboard_spec_gen.go

@@ -753,6 +753,9 @@ type Spec struct {
 	// List of dashboard panels
 	Panels []any `json:"panels,omitempty"`
 
+	// When set to true, the dashboard will load all panels in the dashboard when it's loaded.
+	Preload *bool `json:"preload,omitempty"`
+
 	// Refresh rate of dashboard. Represented via interval string, e.g. "5s", "1m", "1h", "1d".
 	Refresh *string `json:"refresh,omitempty"`