ci: remove unnecessary installs of the package

Author: adosar

.github/workflows/pylint.yaml

@@ -15,6 +15,5 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install pylint
-          pip install .
       - name: Run pylint
         run: pylint src/aidsorb/

.github/workflows/unittest.yaml

@@ -11,9 +11,5 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: "3.x"
-      - name: Install the package
-        run: |
-          python -m pip install --upgrade pip
-          pip install .
       - name: Run unit tests
         run: python -m unittest