Fix dependency installation in GHA

Author: wch

.github/workflows/pytest.yaml

@@ -25,8 +25,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
-          if [ -f requirements-dev.txt ]; then pip install -r requirements-dev.txt; fi
+          pip install -e ".[dev,test]"
       - name: Install
         run: |
           make install
@@ -54,8 +53,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
-          if [ -f requirements-dev.txt ]; then pip install -r requirements-dev.txt; fi
+          pip install -e ".[dev,test]"
       - name: "Build Package"
         run: |
           make dist