Update dependency Grpc.Core.Api to 2.70.0

Author: renovate[bot]

Source/Serilog.Exceptions.Grpc/Serilog.Exceptions.Grpc.csproj

@@ -15,7 +15,7 @@
   </ItemGroup>
 
   <ItemGroup Label="Package References">
-    <PackageReference Include="Grpc.Core.Api" Version="2.67.0" />
+    <PackageReference Include="Grpc.Core.Api" Version="2.70.0" />
   </ItemGroup>
 
 </Project>