gha: fix node deprecation warning

.github/workflows/tests.yml

@@ -39,7 +39,7 @@ jobs:
         password: ${{ secrets.ACR_SERVICE_PRINCIPAL_PASSWORD }}
     steps:
       - name: "Check out code"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: "Build docs"
         run: ./bin/inv_wrapper.sh docs
 
@@ -53,7 +53,7 @@ jobs:
         password: ${{ secrets.ACR_SERVICE_PRINCIPAL_PASSWORD }}
     steps:
       - name: "Check out code"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         # We need to set the safe git directory as formatting relies on git-ls
         # See actions/checkout#766
       - name: "Set the GH workspace as a safe git directory"
@@ -137,14 +137,14 @@ jobs:
       CONAN_CACHE_MOUNT_SOURCE: ~/.conan/
     steps:
       - name: "Log in to ACR"
-        uses: docker/login-action@v2
+        uses: docker/login-action@v3
         with:
           registry: faasm.azurecr.io
           username: ${{ secrets.ACR_SERVICE_PRINCIPAL_ID }}
           password: ${{ secrets.ACR_SERVICE_PRINCIPAL_PASSWORD }}
       # --- Code update ---
       - name: "Check out code"
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: "Conan cache"
         uses: faasm/conan-cache-action@v1
       - name: "Build distributed tests"