cirun integration isn't working well - handle in .cirun repo directly?

We have
https://github.com/conda-forge/admin-requests/blob/07bcab9f435ee4409acd81043f94a5f944ad24d5/examples/example-open-gpu-server.yml#L1

but it's not working for simply adding resources (e.g. the next-bigger one) to already existing policies (e.g. no PR to https://github.com/conda-forge/.cirun after #1746). In case the bot runs precommit before opening a PR, it's also very likely that the integration cannot handle the new linting I was asked to add in https://github.com/conda-forge/.cirun/pull/116.

The integration was also not working for other resources already present for .cirun up until very recently (c.f. https://github.com/conda-forge/admin-requests/pull/1744), meaning this process was never used for anything related to `cirun-azure-windows-{2xlarge,4xlarge}` or `cirun-macos-m4-large`.

Overall, I think this is a bad fit for admin-requests (it also contributes to policies split by resource, which is [problematic](https://github.com/conda-forge/.cirun/issues/122#issuecomment-3507290182) for actual feedstock maintenance), and we should simply handle this in https://github.com/conda-forge/.cirun directly.

The one thing worth keeping IMO is
https://github.com/conda-forge/admin-requests/blob/07bcab9f435ee4409acd81043f94a5f944ad24d5/examples/example-open-gpu-server.yml#L14-L15
but I could imagine we could also trigger this from a reviewed and merged PR in https://github.com/conda-forge/.cirun if necessary.