revert targeting of net5.0

framework/src/Volo.Abp.Core/Volo.Abp.Core.csproj

@@ -4,7 +4,7 @@
   <Import Project="..\..\..\common.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;netstandard2.1;net5.0;net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netstandard2.1;net8.0;net9.0</TargetFrameworks>
     <Nullable>enable</Nullable>
     <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.Core</AssemblyName>
@@ -32,8 +32,10 @@
     <PackageReference Include="System.Linq.Queryable" />
     <PackageReference Include="JetBrains.Annotations" />
     <PackageReference Include="Nito.AsyncEx.Context" />
-    <PackageReference Include="System.Threading.Tasks.Extensions" Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net5.0'))" />
   </ItemGroup>
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
+    <PackageReference Include="System.Threading.Tasks.Extensions" />
+  </ItemGroup>	
   <ItemGroup Condition=" '$(TargetFrameworkIdentifier)' == '.NETStandard' And $([MSBuild]::VersionGreaterThanOrEquals($(TargetFrameworkVersion), '2.1')) ">
     <PackageReference Include="System.ComponentModel.Annotations" />
   </ItemGroup>