[Vibe-d] Disable hanging test 1726 temporarily

[wilzbach]

This test is permanently failing, see e.g.:

https://ci.dlang.io/blue/organizations/jenkins/dlang-org%2Fphobos/detail/PR-5948/2/pipeline

Running ./tests 
core.exception.AssertError@source/app.d(58): Test has hung.
----------------
??:? _d_assert_msg [0x610b6a]
source/app.d:58 pure nothrow @nogc @safe void app.main().__lambda1() [0x555a50]
../../core/vibe/core/core.d:629 void vibe.core.core.makeTaskFuncInfo!(void delegate() @safe).makeTaskFuncInfo(ref void delegate() @safe).callDelegate(vibe.core.core.TaskFuncInfo*) [0x560f27]
../../core/vibe/core/core.d:1269 void vibe.core.core.CoreTask.run() [0x5655a6]
??:? void core.thread.Fiber.run() [0x6468a7]
??:? fiber_entryPoint [0x6465fa]
??:? [0xffffffff]

@s-ludwig's idea from #vibe-d-ci on Slack:

Could it be that the server simply sometimes has higher load? I just had to adjust some tests because Travis tests started to fail often because timers didn't fire within the 20ms tolerance that was previously assumed. This test uses a 20 ms and a 100 ms sleep to generate a particular order, so it would be vulnerable to the same effects. (should probably be rewritten using some form of proper synchronization primitives - not sure how much work that would be)

[dlang-bot]

Thanks for your pull request, @wilzbach!

[PetarKirov]

It seems like more tests need to be disabled..

[wilzbach]

It's finally passing -> I will merge this now, s.t. we get green CIs for now.
Eventually though we should look into making these tests more reliable.

[MartinNowak]

It seems though that it only started hanging just recently.
That asks for a bit more research to figure out what actually goes wrong.
We had issues with this specific test earlier, last time I understood what it's meant to test.

[wilzbach]

It seems though that it only started hanging just recently.

It more or less started with upgrading to vibe-d 0.8.3-alpha:

#93 (this was required for the upcoming std.experimental.allocator breakages).