fix: Use correct secret name for dockerhub password

.github/workflows/unit-tests.yml

@@ -77,7 +77,7 @@ jobs:
         uses: docker/login-action@v3.3.0
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
 
       - name: Start MongoDB
         uses: supercharge/mongodb-github-action@1.11.0