Fix websocket_api timeout test (home-assistant#157204)

Author: jbouwh

tests/components/websocket_api/test_commands.py

@@ -2316,9 +2316,9 @@ async def test_render_template_with_timeout(
     """Test a template that will timeout."""
 
     slow_template_str = """
-{% for var in range(1000) -%}
-  {% for var in range(1000) -%}
-    {{ var }}
+{% for var in range(10000) -%}
+  {% for var in range(10000) -%}
+    {{ "" }}
   {%- endfor %}
 {%- endfor %}
 """