Possible performance regression (vs unmanaged server) if server handler faults

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

2.49.0, C#

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

Windows 11

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

7.0.2

### What did you do?

Investigating server performance in the "fault" case, using a unary handler; exact scenario is [here](https://github.com/protobuf-net/protobuf-net.Grpc/tree/fault-much/examples/grpc) (despite the location, this doesn't use protobuf-net[.Grpc] at all - this is a pure gRPC example)

In this case, "fault" means the handler throws (same numbers obtained from sync throw vs returning faulted task), via the `FAIL` defined at the top of the server files.

`Client` and `Server` are the unmanaged client and server (targeting net48 and net7); `CurrentClient` and `CurrentServer` are the managed client and server (targeting net7 only). Logging has been disabled via `Grpc: None`, and the server console is silent (i.e. this isn't a console logging issue). Permutations can be run simply at the command line (all client/server combinations are configured to use the same endpoint). TLS is not enabled.

success case, unmanaged server, unmanaged client:

- net48 client, net48 server: 197kops/s
- net7 client, net48 server: 204kops/s
- net48 client, net7 server: 377kops/s
- net7 client, net7 server: 393kops/s

failure case, unmanaged server, unmanaged client:

- net48 client, net48 server: 154kops/s
- net7 client, net48 server: 166kops/s
- net48 client, net7 server: 197kops/s
- net7 client, net7 server: 223kops/s

success case, managed server, managed client:

- net7 client, net7 server: 494kops/s

failure case, managed server, managed client:

- net7 client, net7 server: 116kops/s

### What did you expect to see?

the failure case might perhaps have lower performance than success, but within acceptable bounds

### What did you see instead?

the failure case is significantly slower (approx 1/4 throughput) than the success case, and slower than the unmanaged server

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