upstream-cache is ignored in v13

[TheArcaneBrony]

https://github.com/spacebarchat/server/actions/runs/20292039522/job/58278301630

Note how it uploads everything it fetched from cache.nixos.org to the nix cache.

  2025-12-17T05:00:49.241743Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1gvi648mh6716y0d94cjrlihgz20vlxf-unit-dbus.service' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:00:50.797164Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1i69p13yvgsmzjcv1z86m1arhrjin6wv-fuse-3.17.4' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:00:54.239812Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1ml33whp0z61f92xn8z8y6pd6j6l122l-system-path' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:00:55.569850Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1mpnwhj3k5y6m2vm7aw9j1pj5396gr1c-unit-post-resume.service' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:00:57.158606Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1n8zi78n7zlqwky7jj050d1mw5cvmflr-bash-interactive-5.3p3-doc' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:00:58.788436Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1py317vp19frfbfwqzxdygh04lyar4cy-iptables-1.8.11-lib' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:00.237324Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1wjrg5dj3k6r6jwmiib8rn6811zdzvhy-time-1.9' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:01.620020Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1xbk47wcb7i1m39xhsadn0c259rjjnp1-hostname-debian-3.25-man' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:02.899286Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/1ya0bgawfq7jjnxgwa53hpvlym73l63f-unit-script-pre-sleep-start' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:04.476475Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/20axvl7mgj15m23jgmnq97hx37fgz7bk-diffutils-3.12' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:05.804031Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/20s3y0c7l42y3azfqrcs0l10jih0l19h-security-wrapper-sg-x86_64-unknown-linux-musl' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:07.099273Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/27rz8qnmjyff0bpdrq56hjdgsq8vphii-aws-c-compression-0.3.1' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:08.413055Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/29aw86d9xdb5abrqdr9wizgb44b6l1vb-hostname-debian-3.25' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:09.790684Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/2g7r19hw2g5z871hhzam6qkc9jn8gfpl-gawk-5.3.2-man' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:11.141459Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/2hcc69h742hq2mqq0r3r2dh56zi9cwsf-unit-kmod-static-nodes.service' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:13.059035Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/2ksb8q5xj5bn0jrvq4gbgglskn4qdbiw-ncurses-6.5-man' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214
  2025-12-17T05:01:14.460798Z  INFO magic_nix_cache::gha: Uploaded '/nix/store/2n0wdr38w7ibms8l0d9wp7a3axa3zk08-lvm2-2.03.35' to the GitHub Action Cache
    at magic-nix-cache/src/gha.rs:214