ci/multiple discussions

[baywet]

fixes #202

[baywet]

This does multiple things:

• Switches to using gh CLI instead of octokit to execute the GraphQL queries. I suspect ocktokit retries in some very specific cases, but the task does seem to be logging retrials. The CLI should be.
• Adds a step to check whether the agenda item already exsits.

https://github.com/OAI/Overlay-Specification/actions/runs/18911572019/job/53983471269

Unfortunately, the discussions are not available in the GitHub CLI directly, which would make all of that simpler. And the extensions are disappointing to say the least. Additionally, the discussions don't seem to be available with REST endpoints for some reason.
The multiple creations could very well be a fluke of the backend graphQL resolver, in which case I'm afraid there won't be much of a way to solve it on our end. But these changes should add a bit more "safety" to this automation.

[lornajane]

I think this is why we stuck with issues in the main OpenAPI project! Discussions are a nice idea but they're not very linear and they're less well supported. I'll review when I can (thank you for the explanation of the changes, that helps a lot!)

[baywet]

yeah from a documentation, API, and CLI perspective, it looks like they stopped the work midway through... For example: why is there a REST API for teams discussions (never used those), but not for repository discussions?