ci: update action versions

Author: rossengeorgiev

.github/workflows/testing_initiative.yml

@@ -46,9 +46,9 @@ jobs:
             python-version: pypy-3.6
             no-coverage: 1
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python Env
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Display Python version
@@ -94,9 +94,9 @@ jobs:
           - ubuntu-20.04
         python-version: [3.6]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python Env
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Display Python version