Local CI testing using Nektos/Act fails but remote GH Actions succeeds

My GitHub Actions workflow succeeds remotely but when running locally using Act, I get the following error:

SQLSTATE[HY000] [1045] Access denied for user 'root'@'172.18.0.1' (using password: YES) (Connection: mysql, SQL: select table_name as `name`, (data_length + index_length) as `size`, table_comment as `comment`, engine as `engine`, table_collation as `collation` from information_schema.tables where table_schema = 'laravel_app' and table_type in ('BASE TABLE', 'SYSTEM VERSIONED') order by table_name)

I have verified that my database credentials are correct by executing mysql -u root -p on the MySQL Docker container and entering a blank password. I have also tried removing the MYSQL_ALLOW_EMPTY_PASSWORD: true line, adding MYSQL_ROOT_PASSWORD: password, and updating my .env.testing DB_PASSWORD accordingly. I have tried adding a step to clear the cache before running the migrations. I'm at a loss for ideas at this point, so any advice is appreciated.

Workflow:

name: Tests

on: [push, pull_request]

jobs:
  tests:
    name: Run tests
    runs-on: ubuntu-latest

    services:
      mysql:
        image: mysql:latest
        env:
          MYSQL_ALLOW_EMPTY_PASSWORD: true
          MYSQL_DATABASE: database
        ports:
          - 3306:3306
        options: --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=5s --health-retries=3

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup PHP
        uses: shivammathur/setup-php@v2
        with:
          php-version: "8.3"
          extensions: ctype, curl, dom, fileinfo, filter, hash, mbstring, openssl, pcre, pdo, pdo_mysql, session, tokenizer, xml

      - name: Get composer cache directory
        id: composer-cache
        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT

      - name: Cache dependencies
        uses: actions/cache@v4
        with:
          path: ${{ steps.composer-cache.outputs.dir }}
          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
          restore-keys: ${{ runner.os }}-composer-

      - name: Install dependencies
        run: composer install --no-progress --no-interaction --prefer-dist --optimize-autoloader

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: "*"
          cache: "npm"

      - name: Install npm dependencies
        run: npm ci --no-fund

      - name: Build assets
        run: npm run build

      - name: Prepare the application
        run: |
          php -r "file_exists('.env') || copy('.env.testing', '.env');"

      - name: Run migrations
        run: php artisan migrate --no-interaction -vvv

      - name: Execute tests
        run: php artisan test

.env.testing:

APP_NAME="Laravel App"
APP_ENV=testing
APP_KEY=base64:+bYGbgBSkFtfCyonpttiBWbv9q1w2MPkt4kpWJaUFCM=
APP_DEBUG=true
APP_URL=http://localhost

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=database
DB_USERNAME=root
DB_PASSWORD=

QUEUE_CONNECTION=database
BROADCAST_DRIVER=log
SESSION_DRIVER=array
CACHE_DRIVER=array