github: Upgrade deprecated actions to newer ones

The previous ones use Node 16 which now is deprecated.

.github/workflows/test-libcxx.yml

@@ -24,7 +24,7 @@ jobs:
       LLVM_VERSION: ${{steps.get-parameters.outputs.LLVM_VERSION}}
     steps:
       - name: Download build parameters
-        uses: dawidd6/action-download-artifact@v2
+        uses: dawidd6/action-download-artifact@v3
         with:
           workflow: build.yml
           workflow_conclusion: success
@@ -52,7 +52,7 @@ jobs:
         run: |
           choco install ninja
       - name: Download toolchain
-        uses: dawidd6/action-download-artifact@v2
+        uses: dawidd6/action-download-artifact@v3
         with:
           workflow: build.yml
           workflow_conclusion: success
@@ -68,7 +68,7 @@ jobs:
           echo "c:\llvm-mingw\bin" | Out-File -FilePath $Env:GITHUB_PATH -Encoding utf8 -Append
           echo "c:\llvm-mingw\python\bin" | Out-File -FilePath $Env:GITHUB_PATH -Encoding utf8 -Append
           echo "PYTHON_EXE=c:/llvm-mingw/python/bin/python3.exe" | Out-File -FilePath $Env:GITHUB_ENV -Encoding utf8 -Append
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Checkout llvm-project
         env:
           LLVM_VERSION: ${{needs.prepare.outputs.LLVM_VERSION}}