Fix System.Net.Http package refernce and remove not needed target frameworks

Author: Suiram1701

WebUntisAPI.Client/WebUntisAPI.Client.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net6.0;net7.0;net6.0-windows;net7.0-windows;net6.0-android;net7.0-android;net7.0-ios;net47;net481</TargetFrameworks>
+    <TargetFrameworks>net6.0;net7.0;net47;net481</TargetFrameworks>
     <ImplicitUsings>disable</ImplicitUsings>
     <Nullable>disable</Nullable>
     <GenerateDocumentationFile>True</GenerateDocumentationFile>
@@ -25,16 +25,18 @@
     <None Include="..\LICENSE.txt">
       <Pack>True</Pack>
       <PackagePath>\</PackagePath>
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
     <None Include="..\README.md">
       <Pack>True</Pack>
       <PackagePath>\</PackagePath>
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
-    <PackageReference Include="System.Net.Http" Version="4.3.4" />
+	  <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
+	  <PackageReference Condition="'$(TargetFramework)' == 'net47' or '$(TargetFramework)' == 'net481'" Include="System.Net.Http" Version="4.3.4" />
   </ItemGroup>
 
 </Project>