[CI] SocketStreamTest failing on CI

[MarcusDenker]

Bug description
some tests in SocketStreamTest are failing:

on Mac:

• testFlushOtherEndClosed – MacOSX64.Network.Tests.SocketStreamTest
• testNextPutAllFlushOtherEndClosed – MacOSX64.Network.Tests.SocketStreamTest

on Linux:

• testFlushLargeMessageOtherEndClosed – Unix64.Network.Tests.SocketStreamTest

[Rinzwind]

These tests were added in pull request #15984 which was merged in commit 9a4b8d5.

That commit was used in builds 1336, 1337 and 1338 of the ‘Pharo12’ Jenkins job. Those all had #testFlushOtherEndClosed fail on macOS and #testFlushLargeMessageOtherEndClosed on Linux.

In build 1442, #testFlushOtherEndClosed and #testNextPutAllFlushOtherEndClosed failed on macOS, and #testFlushLargeMessageOtherEndClosed failed on Linux.

@daniels220: Could you check what the cause of those failures might be and how that can be fixed?

[daniels220]

This is fixed in #16172, which is a redo of a close follow-on to #15984. I meant to remind about getting it merged, but I've been unexpectedly busy. It would be great if it could be merged in time for Pharo 12—like I said, it's a really close follow-on to #15984, that just got roadblocked by a mistake on my part with the Semaphore API and then I never got back around to it. But, I understand if this is outside the scope of what's acceptable after code freeze. In that case I can move over the specific change that fixes the test, which is just adding a wait in an appropriate spot.

@guillep sounded like you were going to look at #16172, but it looks like it fell through the cracks?