Import zeroconf in the executor to avoid blocking the event loop (#111591)

This one takes ~0.45s on the green

homeassistant/components/zeroconf/manifest.json

@@ -4,6 +4,7 @@
   "codeowners": ["@bdraco"],
   "dependencies": ["network", "api"],
   "documentation": "https://www.home-assistant.io/integrations/zeroconf",
+  "import_executor": true,
   "integration_type": "system",
   "iot_class": "local_push",
   "loggers": ["zeroconf"],