switch e2e tests to xlarge queue

.buildkite/pipeline.yaml

@@ -15,9 +15,9 @@ steps:
 
   - label: ":chains: End-to-End Tests"
     agents:
-      # We use a medium sized instance instead of the normal small ones because
+      # We use a xlarge sized instance instead of the normal small ones because
       # e2e tests otherwise take +-8min
-      queue: "medium"
+      queue: "xlarge"
     command:
       # TODO: Remove hacky chmod for BuildKite
       - "echo '--- Setup'"
@@ -96,7 +96,7 @@ steps:
           image: "node:10"
 
   - wait
- 
+
   - label: "🐴 Trigger riot-web"
     trigger: "riot-web"
     branches: "develop"