Bump GitHub Actions in dotnet.yml (#5)

actions/checkout v4 -> v6 and actions/setup-dotnet v1 -> v5. Drop the
stale inline comment that referenced the 3.1 channel.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: stidsborg

.github/workflows/dotnet.yml

@@ -12,12 +12,12 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         submodules: 'true'
-    - uses: actions/setup-dotnet@v1
+    - uses: actions/setup-dotnet@v5
       with:
-        dotnet-version: '10.0.x' # SDK Version to use; x will use the latest version of the 3.1 channel
+        dotnet-version: '10.0.x'
     - name: Start containers
       run: docker compose -f "./docker-compose.yml" up -d --build           
     - name: Build