build: update MSBuild referenced by FAKE

Author: Tarmil

paket.lock

@@ -129,10 +129,10 @@ NUGET
       FSharp.Core (>= 4.7.2)
       System.Reactive (>= 5.0 < 6.0)
     FSharp.Core (9.0.100)
-    Microsoft.Build.Framework (17.11.4)
-    Microsoft.Build.Utilities.Core (17.11.4)
-      Microsoft.Build.Framework (>= 17.11.4)
-      Microsoft.NET.StringTools (>= 17.11.4)
+    Microsoft.Build.Framework (17.12.6)
+    Microsoft.Build.Utilities.Core (17.12.6)
+      Microsoft.Build.Framework (>= 17.12.6)
+      Microsoft.NET.StringTools (>= 17.12.6)
       System.Collections.Immutable (>= 8.0)
       System.Configuration.ConfigurationManager (>= 8.0)
     Microsoft.NET.StringTools (17.12.6)