PR-check - use actions/checkout instead of git clone w redirect

The git redirect is left behind in self-hosted runners, which is not a
good idea.

.github/workflows/PR-check.yml

@@ -47,10 +47,11 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
         - uses: actions/checkout@v4
-        - name: Get scripts internal...
-          run: | 
-                git config --global url."https://${{ secrets.ACCESS_TOKEN }}@github.com/".insteadOf "git@github.com:"
-                git clone git@github.com:PelionIoT/scripts-internal.git
+        - uses: actions/checkout@v4
+          with:
+            repository: 'PelionIoT/scripts-internal'
+            token: ${{ secrets.ACCESS_TOKEN }}
+            path: 'java-coap/scripts-internal'
         - name: Run no-more-lines w pysh-check 
           run: |
                 sudo apt install pycodestyle pydocstyle black