Updated GH actions CI version. (#119)

Author: p-costa

.github/workflows/compile.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
       with:
         submodules: true
     - name: install software

.github/workflows/runs.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
       with:
         submodules: true
     - name: install software to compile CaNS