Added async generator support in bulk helper

[delvedor]

Now you can use an async generator as datasource in the bulk helper!

const { Client } = require('@elastic/elasticsearch')

async function * generator () {
  const dataset = [
    { user: 'jon', age: 23 },
    { user: 'arya', age: 18 },
    { user: 'tyrion', age: 39 }
  ]
  for (const doc of dataset) {
    yield doc
  }
}

const client = new Client({ node: 'http://localhost:9200' })
const result = await client.helpers.bulk({
  datasource: generator(),
  onDocument (doc) {
    return {
      index: { _index: 'my-index' }
    }
  }
})

console.log(result)

[github-actions]

The backport to 7.x failed:

The process 'git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-7.x 7.x
# Navigate to the new working tree
cd .worktrees/backport-7.x
# Create a new branch
git switch --create backport-1138-to-7.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick df17fb99d06b15042f235b115ee8d0f1d0225c30
# Push it to GitHub
git push --set-upstream origin backport-1138-to-7.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-7.x

Then, create a pull request where the base branch is 7.x and the compare/head branch is backport-1138-to-7.x.