upgrade coverlet.collector 8.0.0

Author: ikpil

test/Box2D.NET.Test/Box2D.NET.Test.csproj

@@ -15,7 +15,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="coverlet.collector" Version="6.0.4">
+    <PackageReference Include="coverlet.collector" Version="8.0.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>