fix: Update GitHub Actions to v4 to fix deprecated actions

Author: Nonanti

.github/workflows/ci.yml

@@ -11,10 +11,10 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Setup .NET
-      uses: actions/setup-dotnet@v3
+      uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '9.0.x'
 
@@ -31,7 +31,7 @@ jobs:
       run: dotnet pack src/CodeContext.CLI/CodeContext.CLI.csproj --configuration Release --output ./artifacts
 
     - name: Upload artifacts
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: nuget-packages
         path: ./artifacts/*.nupkg