feat: generate results with gateway-conformance

[laurentsenta]

Contributes to #442

Work in progress, see runs in fork, large run

• [x] create a gateways.txt file we can import from Ci
• [x] use the report.json in the frontend instead of gateways.ts (single source of truth)
• [x] call the conformance workflow for every gateway
• [x] gather results into a single job
• [x] aggregates all these results into assets we can load in the frontend
• [x] generate intermediate step output per gateway if possible
• [x] define the "right" workflow to commit report.json
• [x] generate a minimal output.md in the action
• [x] find a way to "hide" the failure state on expected failure (not all tests passing)
• [x] undo the dependency on gateway fork (needs the dashboard PR)

[welcome[bot]]

Thank you for submitting this PR! A maintainer will be here shortly to review it. We are super grateful, but we are also overloaded! Help us by making sure that:

• The context for this PR is clear, with relevant discussion, decisions and stakeholders linked/mentioned.

• Your contribution itself is clear (code comments, self-review for the rest) and in its best form. Follow the code contribution guidelines if they apply.

Getting other community members to do a review would be great help too on complex PRs (you can ask in the chats/forums). If you are unsure about something, just leave us a comment. Next steps:

• A maintainer will triage and assign priority to this PR, commenting on any missing things and potentially assigning a reviewer for high priority items.

• The PR gets reviews, discussed and approvals as needed.

• The PR is merged by maintainers when it has been approved and comments addressed.

We currently aim to provide initial feedback/triaging within two business days. Please keep an eye on any labelling actions, as these will indicate priorities and status of your contribution. We are very grateful for your contribution!

[SgtPooki]

I will be diving into this PR shortly. Thanks for all your hard work here @laurentsenta and @whizzzkid