Update github cache action to non-deprecated version

Author: Fryyyyy

.github/workflows/install_test.yml

@@ -28,7 +28,7 @@ jobs:
       run: |
         python -m pip install poetry
     - name: Cache the virtualenv
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ./.venv
         key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}

.github/workflows/install_test_coverage.yml

@@ -27,7 +27,7 @@ jobs:
       run: |
         python -m pip install poetry
     - name: Cache the virtualenv
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ./.venv
         key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}

.github/workflows/install_test_setup_py.yml

@@ -25,7 +25,7 @@ jobs:
       run: |
         python -m pip install poetry
     - name: Cache the virtualenv
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ./.venv
         key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}

.github/workflows/pylint_and_mypy.yml

@@ -20,7 +20,7 @@ jobs:
       run: |
         python -m pip install poetry
     - name: Cache the virtualenv
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ./.venv
         key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}