Revert "Explicitly enable BF for WinForms and WPF in Microsoft.NET.Sdk.targets" (#49562)

Reverts #33004. This was a workaround for #32969 which was fixed in 8.0 (at least the BinaryFormatter portion). The workaround was intended to be removed once that underlying issue was fixed.

Author: elinor-fung

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.targets

@@ -194,7 +194,6 @@ Copyright (c) .NET Foundation. All rights reserved.
     <!-- controls warn as error -->
     <_BinaryFormatterObsoleteAsError>true</_BinaryFormatterObsoleteAsError>
     <!-- controls runtime behavior (AppContext & trimming) -->
-    <EnableUnsafeBinaryFormatterSerialization Condition="'$(EnableUnsafeBinaryFormatterSerialization)' == '' AND '$(_ProjectTypeRequiresBinaryFormatter)' == 'true'">true</EnableUnsafeBinaryFormatterSerialization>
     <EnableUnsafeBinaryFormatterSerialization Condition="$([MSBuild]::VersionGreaterThanOrEquals($(TargetFrameworkVersion), '8.0')) AND '$(_ProjectTypeRequiresBinaryFormatter)' != 'true'">false</EnableUnsafeBinaryFormatterSerialization>
   </PropertyGroup>