ignore CI Stats failures in flaky test jobs

[spalger]

Flaky test jobs are another place where we should ignore failures to ship CI Stats. See #90851

[elasticmachine]

Pinging @elastic/kibana-operations (Team:Operations)

[brianseeders]

👍

[kibanamachine]

Backport result

{"level":"info","message":"POST https://api.github.com/graphql (status: 200)"}
{"level":"info","message":"POST https://api.github.com/graphql (status: 200)"}
{"meta":{"labels":["Team:Operations","auto-backport","release_note:skip","v7.12.0","v8.0.0"],"branchLabelMapping":{"^v8.0.0$":"master","^v7.12.0$":"7.x","^v(\\d+).(\\d+).\\d+$":"$1.$2"},"existingTargetPullRequests":[]},"level":"info","message":"Inputs when calculating target branches:"}
{"meta":["7.x"],"level":"info","message":"Target branches inferred from labels:"}
{"meta":{"killed":false,"code":2,"signal":null,"cmd":"git remote rm kibanamachine","stdout":"","stderr":"error: No such remote: 'kibanamachine'\n"},"level":"info","message":"exec error 'git remote rm kibanamachine':"}
{"meta":{"killed":false,"code":2,"signal":null,"cmd":"git remote rm elastic","stdout":"","stderr":"error: No such remote: 'elastic'\n"},"level":"info","message":"exec error 'git remote rm elastic':"}
{"level":"info","message":"Backporting [{\"sourceBranch\":\"master\",\"targetBranchesFromLabels\":[\"7.x\"],\"sha\":\"4f38d163bf9dda16634bf17d400cfbd6507657b6\",\"formattedMessage\":\"ignore CI Stats failures in flaky test jobs (#90999)\",\"originalMessage\":\"ignore CI Stats failures in flaky test jobs (#90999)\\n\\nCo-authored-by: spalger <spalger@users.noreply.github.com>\",\"pullNumber\":90999,\"existingTargetPullRequests\":[]}] to 7.x"}

Backporting to 7.x:
{"level":"info","message":"Backporting via filesystem"}
{"level":"info","message":"Creating PR with title: \"[7.x] ignore CI Stats failures in flaky test jobs (#90999)\". kibanamachine:backport/7.x/pr-90999 -> 7.x"}
{"level":"info","message":"POST /repos/elastic/kibana/pulls - 201 in 1039ms"}
{"level":"info","message":"Adding assignees to #91003: spalger"}
{"level":"info","message":"POST /repos/elastic/kibana/issues/91003/assignees - 201 in 584ms"}
{"level":"info","message":"Adding labels: backport"}
{"level":"info","message":"POST /repos/elastic/kibana/issues/91003/labels - 200 in 389ms"}
View pull request: https://github.com/elastic/kibana/pull/91003