Fix pubsub flaky tests

[aaronbuchwald]

Removed two instances of t.Skip("FLAKY") in the pubsub package tests #1593

These seem to be causing a CI flake here: https://github.com/ava-labs/hypersdk/actions/runs/11135413552/job/30945383623?pr=1606#step:5:63

The next package that should report test output is the pubsub package, so a deadlock within these tests may explain the failure.

[aaronbuchwald]

https://github.com/ava-labs/hypersdk/actions/runs/11137014736/job/30949749265#step:5:62

[aaronbuchwald]

Running locally on repeat until it fails, it seems to be blocked here:

hypersdk/pubsub/server_test.go

Line 264 in 79f363e

require.Eventually(

(using a 15s timeout where the test typically takes 7s to run when it succeeds)

[aaronbuchwald]

Test failure here: https://github.com/ava-labs/hypersdk/actions/runs/11149074612/job/30987118753?pr=1623#step:5:62

[aaronbuchwald]

Got the test output we were looking for here: https://github.com/ava-labs/hypersdk/actions/runs/11149409503/job/30988235110#step:5:62

The unit tests typically take 3 minutes and this times out after 6 minutes