GitVersionTask - enhancements to csproj file.

- Removed unnecessary target framework
- Ensure Microsoft.Extensions.DependencyInject.dll is included in published output, as it was missing for some reason.

Author: dazinator

src/GitVersionTask/GitVersionTask.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks>net472;netcoreapp2.1;netcoreapp3.1</TargetFrameworks>
+        <TargetFrameworks>net472;netcoreapp2.1</TargetFrameworks>
 
         <PackageId>GitVersionTask</PackageId>
         <Title>GitVersionTask</Title>
@@ -11,10 +11,12 @@
         <DevelopmentDependency>true</DevelopmentDependency>
 
         <LangVersion>8.0</LangVersion>
-    </PropertyGroup>
+    </PropertyGroup>   
 
     <ItemGroup>
-        <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="$(PackageVersion_MicrosoftExtensions)" PrivateAssets="All" />
+        <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="$(PackageVersion_MicrosoftExtensions)" PrivateAssets="All">
+            <Publish>true</Publish>
+        </PackageReference>
         <PackageReference Include="LibGit2Sharp" Version="$(PackageVersion_LibGit2Sharp)" PrivateAssets="All" />
     </ItemGroup>