GHA/non-native: skip OpenBSD WebSocket tests to mitigate job timeouts

GHA/non-native: skip OpenBSD WebSocket tests to mitigate job timeouts

Trying to avoid the occasional ~6-minute long delays seen in the OpenBSD
since last week. The long delay causes the CI job to timeout and fail:
https://github.com/curl/curl/actions/workflows/non-native.yml?page=2&query=branch%3Amaster

The exact reason is or test number is unknown. I base this attempt on
looking at the first occurrences and possible patches that may be
related.

The issue was first seen in CI within PR #17136:
```
[...]
Wed, 07 May 2025 07:10:30 GMT test 3014...[Check if %{num_headers} returns correct number of headers]
Wed, 07 May 2025 07:10:30 GMT s-p----e--- OK (1743 out of 1778, remaining: 00:02, took 0.195s, duration: 01:43)
Wed, 07 May 2025 07:10:30 GMT test 3016...[GET a directory using file://]
[long delay here]
Wed, 07 May 2025 07:16:17 GMT -------
Wed, 07 May 2025 07:16:17 GMT Error: The operation was canceled.
```
Ref: https://github.com/curl/curl/actions/runs/14877264415/job/41776966626#step:3:5566
Ref: https://github.com/curl/curl/actions/runs/14900320627/job/41850699301#step:3:5561 (next in PR)

Then in master, shortly after merging it via d3594be6531df3d5eafcdd09f84ad9dee1777028:
```
[...]
Mon, 02 Jun 2025 09:23:55 GMT test 3201...[HTTP GET when PROXY Protocol enabled and spoofed client IP]
Mon, 02 Jun 2025 09:23:55 GMT --p----e--- OK (1777 out of 1788, remaining: 00:00, took 0.222s, duration: 01:42)
Mon, 02 Jun 2025 09:23:55 GMT RUN: failed to start the HTTP/2 server
Mon, 02 Jun 2025 09:23:55 GMT test 3202...[HTTP-IPv6 GET with PROXY protocol with spoofed client IP]
[long delay here]
Mon, 02 Jun 2025 09:29:48 GMT --p----e--- OK (1778 out of 1788, remaining: 00:00, took 0.1
Mon, 02 Jun 2025 09:29:48 GMT Error: The operation was canceled.
```
Ref: https://github.com/curl/curl/actions/runs/15388587165/job/43292652793#step:3:5097
Ref: https://github.com/curl/curl/actions/runs/15390589464/job/43298911578#step:3:5097 (next in master)

Closes #17562