Update dotnet monorepo to v8

Author: renovate[bot]

src/DotnetDispatcher.Core/DotnetDispatcher.Core.csproj

@@ -23,6 +23,6 @@
     </ItemGroup>
 
     <ItemGroup>
-        <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="7.0.0" />
+        <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.0" />
     </ItemGroup>
 </Project>

test/DotnetDispatcher.Tests/DotnetDispatcher.Tests.csproj

@@ -10,7 +10,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="7.0.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.1" />
     <PackageReference Include="System.Net.Http" Version="4.3.4" />
     <PackageReference Include="xunit" Version="2.5.0" />