Use global.json to specify .NET SDK version.

Author: bgrainger

.github/workflows/build.yaml

@@ -17,10 +17,8 @@ jobs:
     steps:
     - uses: actions/checkout@v4
 
-    - name: Set up .NET 6.0
+    - name: Set up .NET
       uses: actions/setup-dotnet@v3
-      with:
-        dotnet-version: 6.0.x
 
     - name: Restore
       run: dotnet restore

global.json

@@ -0,0 +1,6 @@
+{
+  "sdk": {
+    "version": "6.0.400",
+    "rollForward": "latestPatch"
+  }
+}