update: unit test 시 setup python action 삭제

Author: 404Vector

.github/workflows/unit_test.yml

@@ -17,10 +17,6 @@ jobs:
       image: python:${{ matrix.python-version }}
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v3
-      with:
-        python-version: ${{ matrix.python-version }}
     - name: Install OpenEXR
       run: |
         apt-get update