fix: python3 및 pip 직접 설치 추가

.github/workflows/lotto-buy.yml

@@ -12,8 +12,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: 의존성 설치
-        run: pip3 install -r requirements.txt
+      - name: Python 및 의존성 설치
+        run: |
+          apt-get update -qq
+          apt-get install -y python3 python3-pip python3-venv
+          pip3 install -r requirements.txt
 
       - name: Chrome 설치
         uses: browser-actions/setup-chrome@v1