gRPC connection doesn't respect Timeout parameter

### Brief summary

The grpc k6 tests, specifically with stream connection, are a bit special as we can't really use k6 test iterator and all test execution happens in a single test iteration.
The test iteration only completes when grpc connection is closed, means all test workload should happen inside js iteration (for loop for ex).
This makes test duration none deterministic and test run completes with never finished iteration.

Unfortunately the `Timeout` parameter in the `connect` method doesn't work and there seems to be no way to gracefully finish test.

### k6 version

v0.56.0

### OS

macos

### Docker version and image (if applicable)

_No response_

### Steps to reproduce the problem

1. Have timeout set in the grpc client connect
```import grpc from "k6/net/grpc";
import { check } from "k6";

const client = new grpc.Client();
client.load(["./src/support/echo/server"], "helloworld.proto");

export default function () {
client.connect("127.0.0.1:9999", { plaintext: true, timeout: 1 });

const response = client.invoke("helloworld.Greeter/SayHello", {
name: "Tiko",
});

check(response, {
"status is OK": (res) => res && res.status === grpc.StatusOK,
"response message exists": (res) => res && res.message,
});

console.log(`Response: ${JSON.stringify(response.message)}`);

client.close();
}
```

2. Run test
```
(base) tiko@tiko-workstation k6 % ./k6 run 1.test.js

/\ Grafana /‾‾/
/\ / \ |\ __ / /
/ \/ \ | |/ / / ‾‾\
/ \ | ( | (‾) |
/ __________ \ |_|\_\ \_____/

execution: local
script: 1.test.js
output: -

scenarios: (100.00%) 1 scenario, 1 max VUs, 10m30s max duration (incl. graceful stop):
* default: 1 iterations for each of 1 VUs (maxDuration: 10m0s, gracefulStop: 30s)

INFO[0002] Response: {"message":"Hello Tiko"} source=console

✓ status is OK
✓ response message exists

checks...............: 100.00% 2 out of 2
data_received........: 153 B 76 B/s
data_sent............: 270 B 135 B/s
grpc_req_duration....: avg=2s min=2s med=2s max=2s p(90)=2s p(95)=2s
iteration_duration...: avg=2s min=2s med=2s max=2s p(90)=2s p(95)=2s
iterations...........: 1 0.499242/s
vus..................: 1 min=1 max=1
vus_max..............: 1 min=1 max=1

running (00m02.0s), 0/1 VUs, 1 complete and 0 interrupted iterations
default ✓ [======================================] 1 VUs 00m02.0s/10m0s 1/1 iters, 1 per VU
(base) tiko@tiko-workstation k6 % ./k6 --version
k6 v0.56.0 (commit/bf9c8a4d86-dirty, go1.23.0, darwin/amd64)

```

### Expected behaviour

grpc connection timeouts before server response. Notice response is 2s

### Actual behaviour

Timeout parameter is no considered. There is no way to make client terminate connection and for test iteration to complete.