[cicd] Fix github rate limit issue (#2667)

## Summary

Fixes
https://github.com/jetify-com/devbox/actions/runs/16847493651/job/47729104601

This is a very specific fix to this job. I think a better solution is to
pass `--extra-access-tokens` flag into nix commands that may interact
with github.

## How was it tested?

Not sure how to test.

## Community Contribution License

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project
maintainers under the terms of the
[Apache 2 License](https://www.apache.org/licenses/LICENSE-2.0).

By creating this pull request, I represent that I have the right to
license the
contributions to the project maintainers under the Apache 2 License as
stated in
the
[Community Contribution
License](https://github.com/jetify-com/opensource/blob/main/CONTRIBUTING.md#community-contribution-license).

Author: mikeland73

.github/workflows/cache-upload.yml

@@ -22,6 +22,9 @@ env:
   DEVBOX_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
   DEVBOX_DEBUG: 1
   GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  # I think this should be added to individual nix commands within devbox, but this is quick fix for now
+  NIX_CONFIG: |
+    access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
 
 jobs:
   upload-cache: