解放！

Author: hotate29

.github/workflows/ci.yml

@@ -8,7 +8,6 @@ on:
 env:
   CARGO_TERM_COLOR: always
   RUST_BACKTRACE: 1
-  RUST_TEST_THREADS: 1
   CARGO_PROFILE_TEST_DEBUG: 0
   DATABASE_URL: postgres://db_user:db_pass@localhost:5432/test_db
 
@@ -60,7 +59,7 @@ jobs:
         run: cargo test --no-run --workspace --locked --verbose
 
       - name: Run tests
-        run: cargo test --workspace --locked --verbose -- --test-threads=1
+        run: cargo test --workspace --locked --verbose
 
   frontend_test:
     name: Run frontend tests

atcoder-problems-backend/README.md

@@ -71,7 +71,7 @@ cargo run --bin fix_invalid_submissions
 
 ```bash
 docker-compose up -d
-docker-compose exec backend-development cargo test --workspace -- --test-threads=1
+docker-compose exec backend-development cargo test --workspace
 ```
 
 ## Format