fix CI unit test runs

Author: mstream

.github/workflows/check.yml

@@ -14,6 +14,8 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
+      - name: Set up direnv
+        uses: HatsuneMiku3939/direnv-action@v1
       - name: Set up Nix
         uses: cachix/install-nix-action@v30
         with: