Mark webserver and captive portal as not available on rp2040 (#4023)

esphome/components/web_server/__init__.py

@@ -75,6 +75,7 @@ CONFIG_SCHEMA = cv.All(
         }
     ).extend(cv.COMPONENT_SCHEMA),
     cv.only_with_arduino,
+    cv.only_on(["esp32", "esp8266"]),
     default_url,
     validate_local,
 )