only preload app plugins (#42434) (#42477)

(cherry picked from commit 9c9e79da4f)

Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>

pkg/api/frontendsettings.go

@@ -155,7 +155,7 @@ func (hs *HTTPServer) getFrontendSettingsMap(c *models.ReqContext) (map[string]i
 		return nil, err
 	}
 
-	pluginsToPreload := []*PreloadPlugin{}
+	pluginsToPreload := make([]*PreloadPlugin, 0)
 	for _, app := range enabledPlugins[plugins.App] {
 		if app.Preload {
 			pluginsToPreload = append(pluginsToPreload, &PreloadPlugin{
@@ -176,14 +176,6 @@ func (hs *HTTPServer) getFrontendSettingsMap(c *models.ReqContext) (map[string]i
 		if isDefault, _ := dsM["isDefault"].(bool); isDefault {
 			defaultDS = n
 		}
-
-		module, _ := dsM["module"].(string)
-		if preload, _ := dsM["preload"].(bool); preload && module != "" {
-			pluginsToPreload = append(pluginsToPreload, &PreloadPlugin{
-				Path:    module,
-				Version: dsM["info"].(map[string]interface{})["version"].(string),
-			})
-		}
 	}
 
 	panels := map[string]interface{}{}
@@ -192,13 +184,6 @@ func (hs *HTTPServer) getFrontendSettingsMap(c *models.ReqContext) (map[string]i
 			continue
 		}
 
-		if panel.Preload {
-			pluginsToPreload = append(pluginsToPreload, &PreloadPlugin{
-				Path:    panel.Module,
-				Version: panel.Info.Version,
-			})
-		}
-
 		panels[panel.ID] = map[string]interface{}{
 			"id":            panel.ID,
 			"module":        panel.Module,