cleanup and try to stabilize weather e2e tests (#3848)

The weather e2e tests are failing sometimes, failing is not really
reproducable.

After changing `updateDom(0)` to `updateDom(300)` in `weather.js` it
seems to work (we will se if it really works in the long term).

This PR contains some other weather e2e changes/cleanups/simplifying.

modules/default/weather/weather.js

@@ -163,7 +163,8 @@ Module.register("weather", {
 	// What to do when the weather provider has new information available?
 	updateAvailable () {
 		Log.log("New weather information available.");
-		this.updateDom(0);
+		// this value was changed from 0 to 300 to stabilize weather tests:
+		this.updateDom(300);
 		this.scheduleUpdate();
 
 		if (this.weatherProvider.currentWeather()) {