chore: .env 파일 전체를 하나의 Secret으로 관리하도록 변경

Author: move-hoon

.github/workflows/cd.yml

@@ -24,12 +24,7 @@ jobs:
       - name: Create .env file
         run: |
           mkdir -p src/main/resources
-          cat << EOF > src/main/resources/.env
-          SLACK_WEBHOOK_CREW_DEV_BE=${{ secrets.SLACK_WEBHOOK_CREW_DEV_BE }}
-          SLACK_WEBHOOK_CREW_DEV_FE=${{ secrets.SLACK_WEBHOOK_CREW_DEV_FE }}
-          SLACK_WEBHOOK_CREW_PROD_BE=${{ secrets.SLACK_WEBHOOK_CREW_PROD_BE }}
-          SLACK_WEBHOOK_CREW_PROD_FE=${{ secrets.SLACK_WEBHOOK_CREW_PROD_FE }}
-          EOF
+          echo "${{ secrets.DOTENV_FILE }}" > src/main/resources/.env
 
       - name: Build shadow JAR (default = shadowJar)
         run: ./gradlew build