Update nbgv to ship MSBuild 16.9

AArnott · AArnott · commit c13d166c4ef1 · 2021-09-22T20:36:40.000-06:00
This is the latest version that still supports netcoreapp3.1.
This should fix the problem of parsing msbuild project files with metadata as xml attributes.
diff --git a/src/nbgv/nbgv.csproj b/src/nbgv/nbgv.csproj
@@ -15,7 +15,7 @@
     <PackageReference Include="System.CommandLine" Version="2.0.0-beta1.20574.7" />
     <PackageReference Include="Nerdbank.GitVersioning.LKG" Version="3.4.173-alpha" PrivateAssets="all" />
     <PackageReference Include="System.Diagnostics.Tools" Version="4.3.0" />
-    <PackageReference Include="Microsoft.Build" Version="15.9.20" />
+    <PackageReference Include="Microsoft.Build" Version="16.9.0" />
   </ItemGroup>
 
   <ItemGroup>
