Currently the ecosystem team triages all PRs in the packages repository, but the platform teams also triage all PRs with their platform label. Due to the way PRs in packages work, however, it's relatively common for a PR to not be relevant to all the teams' triages at all times. Common examples:
- One platform team may LGTM a multi-platform PR for their platform's portion, while another platform goes through review for several more weeks.
- A cross-platform PR may not have high-level design approval from the ecosystem owner, at which point platform implementation review is premature.
To avoid PRs showing up repeatedly in a platform team's triage when it's not relevant, this adjusts the triage structure:
- Queries for PRs in platform teams query `triage-<platform name>` rather than `platform-<platform name>`
- Ecosystem triage will add the `triage-<platform name>` label during triage when a PR is ready for that platform team's consideration.
- Platform teams can remove the label when it's not relevant to them (e..g, after it's been LGTM'd for that platform).
This also adds a desktop PR query, since there wasn't one, covering the separate platforms. They are separated to allow for more triage flexibility in the future.
