[9.3] (backport #18526) Remove unused gradle tasks

[mergify]

Release notes

[rn:skip]

What does this PR do?

This PR removes unused gradle tasks. It also removes a script from CI that is unused.

Closes #18476

---

This is an automatic backport of pull request #18526 done by Mergify.

[mergify]

Cherry-pick of 28c810d has failed:

On branch mergify/bp/9.3/pr-18526
Your branch is up to date with 'origin/9.3'.

You are currently cherry-picking commit 28c810d7.
  (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/rm <file>..." as appropriate to mark resolution)
	both modified:   build.gradle
	deleted by them: ci/ci_docs.sh

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

[github-actions]

🤖 GitHub comments

Just comment with:

• run docs-build : Re-trigger the docs validation. (use unformatted text in the comment!)
• /run exhaustive tests : Run the exhaustive tests Buildkite pipeline.

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 89e04c4

History

• 💔 Build #4091 failed 10899ac

cc @donoghuc