Update Verify.ExceptionParsing.csproj

Author: SimonCropp

src/Verify.ExceptionParsing/Verify.ExceptionParsing.csproj

@@ -3,7 +3,6 @@
     <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
-    <Using Include="System.ReadOnlySpan&lt;System.Char&gt;" Alias="CharSpan" />
     <PackageReference Include="Polyfill" Version="1.16.0" PrivateAssets="all" />
     <PackageReference Include="ProjectDefaults" Version="1.0.90" PrivateAssets="all" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" Condition="$(Configuration) == 'Release'" />