[7.17](backport #43254) Skip flaky vsphere datastore TestFetchEventContents

[mergify]

Skip flaky test from #43252

---

This is an automatic backport of pull request #43254 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of cd2ff13 has failed:

On branch mergify/bp/7.17/pr-43254
Your branch is up to date with 'origin/7.17'.

You are currently cherry-picking commit cd2ff1333.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   metricbeat/module/vsphere/datastore/datastore_test.go

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[botelastic]

This pull request doesn't have a Team:<team> label.

[mergify]

This pull request has not been merged yet. Could you please review and merge it @faec? 🙏