Set environment variables to hopefully allow cargo to see the pre-built dependencies

.forgejo/workflows/ci.yml

@@ -113,6 +113,9 @@ jobs:
               mkdir -p /workspace
               tar -x -C /workspace
               cd /workspace/backend
+              # Use pre-built dependencies from the image
+              export CARGO_TARGET_DIR=/app/target
+              export CARGO_REGISTRY_DIR=/usr/local/cargo/registry
               # Build local crates using pre-built external dependencies
               cargo build --release --locked
               cargo test --lib -- --test-threads=1