chore: add github workflow

Author: hulkoba

.github/workflows/ci.yml

@@ -0,0 +1,29 @@
+name: phpseclib3 Tests
+
+on: [push]
+
+jobs:
+  tests:
+    name: Rector Tests
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        php-version: ['8.3', '8.4', '8.5']
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-version }}
+          coverage: none
+
+      - name: Install dependencies
+        run: composer install --no-interaction --prefer-dist
+
+      - name: Run Rector tests
+        run: vendor/bin/phpunit tests