Update .NET SDK

Update .NET SDK to version 8.0.400.

---
updated-dependencies:
- dependency-name: Microsoft.NET.Sdk
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.303",
+    "version": "8.0.400",
     "allowPrerelease": false,
     "rollForward": "latestFeature"
   }