fix: gitlint installation

Latest ubuntu does not allow system wide pip install.
It can be overriden with `--break-system-packages`,
but it's better to create a virtual env.

Signed-off-by: Martin Malina <mmalina@redhat.com>

.github/workflows/pr.yml

@@ -104,14 +104,19 @@ jobs:
         run: docker build -f ./Dockerfile .
   gitlint:
     name: Run gitlint checks
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
           ref: ${{ github.event.pull_request.head.sha }}
       - name: Install gitlint into container
-        run: python -m pip install gitlint
+        run: |
+          python3 -m venv venv
+          source venv/bin/activate
+          python3 -m pip install gitlint
       - name: Run gitlint check
-        run: gitlint --commits origin/${{ github.event.pull_request.base.ref }}..HEAD
+        run: |
+          source venv/bin/activate
+          gitlint --commits origin/${{ github.event.pull_request.base.ref }}..HEAD