Simplify testing workflow

Now that this is the only one actually using this,
the whole complexity here is totally unnecessary

.github/workflows/checks.yml

@@ -12,10 +12,11 @@ permissions:
   contents: read
 
 jobs:
-  docker-build:
+  tests:
     runs-on: ubuntu-latest
 
     steps:
+      - uses: actions/checkout@v4
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
@@ -24,21 +25,20 @@ jobs:
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max
+          load: true
           tags: reverser
 
-  tests:
-    runs-on: ubuntu-latest
-    needs: docker-build
-
-    steps:
-      - uses: actions/checkout@v4
-      - uses: ./.github/prepare-docker-image
+      - name: Set env file
+        run: |
+          cat <<EOT >> .env
+          REVERSER_DATA_PATH=${{ runner.temp }}/reverser
+          EOT
 
       - name: Create DB
-        run: eval $DOCKER_RUN reverser bin/setup
+        run: docker compose run reverser bin/setup
 
       - name: Run Tests
-        run: eval $DOCKER_RUN tests
+        run: docker compose run -e CI=1 tests
 
   rubocop:
     runs-on: ubuntu-latest