Add timeout to dev template renders (#7141)

src/data/ws-templates.ts

@@ -18,6 +18,7 @@ export const subscribeRenderTemplate = (
     template: string;
     entity_ids?: string | string[];
     variables?: object;
+    timeout?: number;
   }
 ): Promise<UnsubscribeFunc> => {
   return conn.subscribeMessage((msg: RenderTemplateResult) => onChange(msg), {

src/panels/developer-tools/template/developer-tools-template.ts

@@ -296,6 +296,7 @@ class HaPanelDevTemplate extends LitElement {
         },
         {
           template: this._template,
+          timeout: 3,
         }
       );
       await this._unsubRenderTemplate;