Update actions versions.

Author: bgrainger

.github/workflows/build.yaml

@@ -15,10 +15,10 @@ jobs:
     runs-on: 'windows-latest'
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v4
 
     - name: Set up .NET 6.0
-      uses: actions/setup-dotnet@v1
+      uses: actions/setup-dotnet@v3
       with:
         dotnet-version: 6.0.x