use v4

Author: BenjaminAbt

.github/workflows/main.yml

@@ -26,12 +26,12 @@ jobs:
           fetch-depth: 0 # avoid shallow clone so nbgv can do its work.
 
       - name: Setup .NET SDK 7.x
-        uses: actions/setup-dotnet@v3
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '7.x'
 
       - name: Setup .NET SDK 8.x
-        uses: actions/setup-dotnet@v3
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: '8.x'