Enable GitHub workflows for PRs with the ok-to-test label

[ivanvc]

Allow running GitHub workflows for pull requests with the ok-to-test label using the prow bot command /ok-to-test. This is already done in most of etcd repositories (refer to the issue etcd-io/etcd#16956 and its PR etcd-io/etcd#16965, or etcd-io/bbolt#631 and etcd-io/bbolt#638).

Refer to etcd's .github/workflows/gh-workflow-approve.yaml and note that in this repository it should only run on the main branch.

This decreases the toil on maintainers as members can trigger tests by commenting /ok-to-test in pull requests.

[ivanvc]

@jmhbnz / @ahrtr, can you help me set this up with "help wanted" and "good first issue" labels? I don't have permission in this repository.

[ivanvc]

Hold on, do we even need this? How is it working if we don't have the workflow in this repository 🤔 . I see that it worked in this pull request: #40 (comment)

Do we even need it in other repositories if it works without the workflow?

EDIT: Never mind, we still need it because it only triggers prow jobs, not GitHub workflows.

SECOND EDIT: On second thought, if we're migrating everything to prow jobs, we may not need this workflow unless we want to keep it as a backup (in case someone adds a GitHub workflow rather than a prow job)

[ahrtr]

I don't have permission in this repository.

Please send a PR to fix this, thx.

[ivanvc]

Please send a PR to fix this, thx.

I wanted to open this to new contributors, but I don't have permission to set the labels.

[ivanvc]

/label help wanted
/label good first issue

[ivanvc]

/help

[ahrtr]

I wanted to open this to new contributors, but I don't have permission to set the labels.

I mean to try to grant you the permission in a PR.

[ivanvc]

I mean to try to grant you the permission in a PR.

Ah, got you. I think I know what it is. I'll take a look at it later today. Thanks!

[Dhairya-Dudhatra]

/assign