[browser][crypto] Remove restraining not supported attribute Primitives (#43387)

* [browser][crypto] Remove restraining not supported attribute

- The modules included within the System.Security.Cryptography.Primitives module should still be available for use outside of browser os.

* Address review comments.  Remove `<IncludePlatformAttributes>` attribute as well

Author: kjpou1

src/libraries/System.Security.Cryptography.Primitives/Directory.Build.props

@@ -2,7 +2,5 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
   </PropertyGroup>
-</Project>
+</Project>