Schemas: Allow nulls in schema for +/-Infinity types (#70958)

* Add null options and remove veneer attributes

* Generate all code, remove old veneer defs

* Remove now-unnecessary error expect

pkg/kinds/dashboard/dashboard_spec_gen.go

@@ -612,13 +612,13 @@ type RangeMap struct {
 	// Range to match against and the result to apply when the value is within the range
 	Options struct {
 		// Min value of the range. It can be null which means -Infinity
-		From float64 `json:"from"`
+		From *float32 `json:"from"`
 
 		// Result used as replacement with text and color when the value matches
 		Result ValueMappingResult `json:"result"`
 
 		// Max value of the range. It can be null which means +Infinity
-		To float64 `json:"to"`
+		To *float32 `json:"to"`
 	} `json:"options"`
 	Type RangeMapType `json:"type"`
 }
@@ -866,7 +866,7 @@ type Threshold struct {
 
 	// Value represents a specified metric for the threshold, which triggers a visual change in the dashboard when this value is met or exceeded.
 	// Nulls currently appear here when serializing -Infinity to JSON.
-	Value float32 `json:"value"`
+	Value *float32 `json:"value"`
 }
 
 // Thresholds configuration for the panel