bump Grpc.Tools dep (#2603)

Author: apolcyn

Directory.Packages.props

@@ -33,7 +33,7 @@
     <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="$(MicrosoftExtensionsPackageVersion)" />
 
     <!-- gRPC -->
-    <PackageVersion Include="Grpc.Tools" Version="2.67.0" />
+    <PackageVersion Include="Grpc.Tools" Version="2.70.0" />
     <PackageVersion Include="Grpc.Core" Version="2.46.6" />
     <PackageVersion Include="Grpc.Core.Api" Version="$(GrpcDotNetPackageVersion)"/>
     <PackageVersion Include="Grpc.Net.Client" Version="$(GrpcDotNetPackageVersion)" />