Data modules: Reject the promise on XHR error

Makes the WordPress data module reject the loading promise on XHR error.
Before this commit, the promise would erroneously resolve even if the
request failed.

Related to #564

packages/playground/wordpress/build/Dockerfile

@@ -188,8 +188,7 @@ RUN cat /root/output/wp.js \
     | sed -E "s#'[^']*wp\.data'#dependencyFilename#g" \
     | sed -E 's#xhr.onerror = #xhr.onerror = onLoadingFailed; const z = #g' \
     | sed -E 's#throw new Error\(xhr.+$#onLoadingFailed(event);#g' \
-    | sed -E 's#runWithFS#runWithFSThenResolve#g' \
-    | sed -E 's#function runWithFSThenResolve#function runWithFSThenResolve() { runWithFS(); resolve(); }; function runWithFS#g' \
+    | sed -E "s#Module\['removeRunDependency'\]\(dependencyFilename\);#Module['removeRunDependency'](dependencyFilename); resolve();#g" \
     > /tmp/wp.js && \
     mv /tmp/wp.js /root/output/wp.js;