Grpc.Net.ClientFactory in unit test causing exception after upgrade to .Net 6.0: The type 'ServiceCollection' exists in both 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' and 'Microsoft.Extensions.DependencyInjection, Version=3.0.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'

### What version of gRPC and what language are you using?
``
``
C#

### What operating system (Linux, Windows,...) and version?
Windows 10

### What runtime / compiler are you using (e.g. .NET Core SDK version `dotnet --info`)
`.NET 6.0.100`

### What did you do?
We had a Unit Test project that we upgraded from .Net 5.0 to .Net 6.0 where we were unit testing a IServiceCollection extension method to inject a gRPC client to the dependency injection container. The unit test in question looks like the following:

```csharp

[Fact]
public void AddNotificationSystemClient_NullAction_ThrowsException()
{
var s = new ServiceCollection();

Action act = () => s.AddNotificationSystemClient((Action)null);

act.Should().Throw();
}

```

The issue is that `Grpc.Net.Clientfactory 2.40.0` has a reference to `Microsoft.Extensions.Http 3.0.3` which causes the following error when building.

```
The type 'ServiceCollection' exists in both 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' and 'Microsoft.Extensions.DependencyInjection, Version=3.0.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'
```

### What did you expect to see?
I expected to be able to compile and run the unit test.

### What did you see instead?

When building the project, I get the following build error:

```
The type 'ServiceCollection' exists in both 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' and 'Microsoft.Extensions.DependencyInjection, Version=3.0.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'
```

### Anything else we should know about your project / environment?

Start with the shown unit test and the PackageReference entries for Grpc.Net.Client and Grpc.Net.ClientFactory 2.40.0, then inspect the resolved Microsoft.Extensions dependency versions in the .NET 6 build. Confirm the fix by compiling and running the test without the duplicate ServiceCollection error.

Written by the indexing model from the issue text.