rem fwk (#175)

Author: bitfaster

BitFaster.Caching/BitFaster.Caching.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net472;net48;netstandard2.0;netcoreapp3.1;net6.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netcoreapp3.1;net6.0</TargetFrameworks>
     <Authors>Alex Peck</Authors>
     <Company />
     <Product>BitFaster.Caching</Product>
@@ -39,7 +39,7 @@
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net472' or '$(TargetFramework)' == 'net48' or '$(TargetFramework)' == 'netstandard2.0'">
+  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
      <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.5.4" />
   </ItemGroup>