OpenAPI: Fix alerting DeleteMuteTiming errors (#91109)

The `GenericPublicError` is not what is actually returned by the API. Using `PublicError` describes the API correctly

pkg/services/ngalert/api/tooling/definitions/provisioning_mute_timings.go

@@ -70,7 +70,7 @@ import (
 //     Responses:
 //       202: MuteTimeInterval
 //       400: ValidationError
-//       409: GenericPublicError
+//       409: PublicError
 
 // swagger:route DELETE /v1/provisioning/mute-timings/{name} provisioning stable RouteDeleteMuteTiming
 //
@@ -78,7 +78,7 @@ import (
 //
 //     Responses:
 //       204: description: The mute timing was deleted successfully.
-//       409: GenericPublicError
+//       409: PublicError
 
 // swagger:route
 

pkg/services/ngalert/api/tooling/definitions/provisioning_templates.go

@@ -13,7 +13,7 @@ package definitions
 //
 //     Responses:
 //       200: NotificationTemplate
-//       404: GenericPublicError
+//       404: PublicError
 
 // swagger:route PUT /v1/provisioning/templates/{name} provisioning stable RoutePutTemplate
 //
@@ -24,8 +24,8 @@ package definitions
 //
 //     Responses:
 //       202: NotificationTemplate
-//       400: GenericPublicError
-//       409: GenericPublicError
+//       400: PublicError
+//       409: PublicError
 
 // swagger:route DELETE /v1/provisioning/templates/{name} provisioning stable RouteDeleteTemplate
 //
@@ -33,7 +33,7 @@ package definitions
 //
 //     Responses:
 //       204: description: The template was deleted successfully.
-//       409: GenericPublicError
+//       409: PublicError
 
 // swagger:parameters RouteGetTemplate RoutePutTemplate RouteDeleteTemplate
 type RouteGetTemplateParam struct {

pkg/services/ngalert/api/tooling/definitions/shared.go

@@ -20,10 +20,3 @@ type ForbiddenError struct {
 	// in: body
 	Body errutil.PublicError `json:"body"`
 }
-
-// swagger:model
-type GenericPublicError struct {
-	// The response message
-	// in: body
-	Body errutil.PublicError `json:"body"`
-}