Clean up GitHub automation for issues that are no longer owned by arch-bom

[dianakhuang]

The GitHub automation automatically puts issues onto our board for repos we own. Now that we have shrunk the list of repos we own, we should update the automation to match it.

A/C:

• Repos we don't own are no longer in automation
• If there's now room for more repos, add the highest priority ones that are missing. (Github imposes a limit on how many we can have.)

Notes:

• Original ticket for auto-adding issues to the board: Auto add arch-bom repo issues to arch-bom project #494

[robrap]

openedx/event-routing-backends#423 is an example ticket that we shouldn't need to prioritize, because we don't own this repo any more.

[robrap]

[open question] Do we want or not want to watch edx-platform? I'd say yes for now. Hopefully it keeps us informed and does not take much time to clean off our board, and we can revisit if it becomes an issue. Let me know if anyone disagrees.

[robrap]

The project workflows for repos we no longer own have been removed.