Upgrade tests are still failing after #55181, an illegal argument exception is thrown:

IllegalArgumentException[Unknown NamedWriteable [org.elasticsearch.xpack.core.XPackFeatureSet$Usage][]];

when the test "Basic test for usage stats on analytics indices" is executed. As there is some background around XPack Usage backward compatibility I prefer to just mute this test and assign the issue.

The failure occurs in the ':x-pack:qa:rolling-upgrade:v7.8.0#twoThirdsUpgradedTest' task.

I've collected the last builds scans:

• https://gradle-enterprise.elastic.co/s/gj5m7daqsm6js
• https://gradle-enterprise.elastic.co/s/hg4zzh2ft5pno
• https://gradle-enterprise.elastic.co/s/7b63xqcokbib2
• https://gradle-enterprise.elastic.co/s/sd6xtj2zhgt66
• https://gradle-enterprise.elastic.co/s/jtfzk6n3w6coo
• https://gradle-enterprise.elastic.co/s/wpfyemdc5o3q2
• https://gradle-enterprise.elastic.co/s/bxa4y6otxlcne

The failure does not reproduce locally.