Update: github action 중복 코드 제거

Author: taenguree

.github/workflows/main.yml

@@ -15,14 +15,6 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
-    - name: set up JDK 17
-      uses: actions/setup-java@v4
-      with:
-        java-version: '17'
-        distribution: 'temurin'
-        cache: gradle
-
     - name: Checkout repository
       uses: actions/checkout@v4