Make sure the build happens in an executable environment (due to serde)

.gitea/workflows/actions.yaml

@@ -25,6 +25,8 @@ jobs:
       - name: Checkout repository code
         uses: actions/checkout@v4
       - name: Run repository tests
+        env:
+          CARGO_TARGET_DIR: /tmp/cargo-target
         run: /run/current-system/sw/bin/nix --extra-experimental-features "nix-command flakes" develop --command bash -c "task test-all"
 
   build-flake: