Flaky tests in 6.2.0

[Apteryks]

Describe the bug
The test_hot_restart_does_not_drop_connections_threads sometimes fail, like:

Finished in 46.952074s, 12.1400 runs/s, 35.8238 assertions/s.
Errors & Failures:

  1) Failure:
TestIntegrationCluster#test_hot_restart_does_not_drop_connections_threads [/tmp/guix-build-ruby-puma-6.2.0.drv-0/source/test/helpers/integration.rb:457]:
Expected: 3000
  Actual: 2999

570 runs, 1682 assertions, 1 failures, 0 errors, 12 skips

To Reproduce
Run the test suite multiple times until it fails.

Expected behavior
Test should always pass.

Desktop (please complete the following information):

• OS: Guix System (GNU/Linux)
• Puma Version 6.2.0.

[Apteryks]

Another one:

S...........................................................................................................................SSSSS................................................Parsing options from the first comment line is deprecated!
............S...SS........................................S.................S..........................................................S........................................................................................................F..............................S.............................................................

Finished in 47.177169s, 12.0821 runs/s, 35.4621 assertions/s.
Errors & Failures:

  1) Failure:
TestIntegrationCluster#test_hot_restart_does_not_drop_connections [/tmp/guix-build-ruby-puma-6.2.0.drv-0/source/test/helpers/integration.rb:447]:
      0 unexpected_response
      0 refused
      0 read timeout
      1 reset
    999 success
    752 success after restart
      2 restart count
Expected no reset errors.
Expected: 0
  Actual: 1

570 runs, 1673 assertions, 1 failures, 0 errors, 13 skips

[MSP-Greg]

@Apteryks I haven't had the time, but we/I will have PR's for this, probably this weekend.

[joshuay03]

Unsure if related, but I'm getting this intermittently on master using the MacOS Sonoma 14.0 Beta when running the same test:

#<Thread:0x000000010768ad00 /Users/joshuayoung/Projects/puma/test/helpers/integration.rb:388 run> terminated with exception (report_on_exception is true):
/Users/joshuayoung/Projects/puma/test/helpers/integration.rb:392:in `initialize': Can't assign requested address - connect(2) for "127.0.0.1" port 54325 (Errno::EADDRNOTAVAIL)
        from /Users/joshuayoung/Projects/puma/test/helpers/integration.rb:392:in `new'
        from /Users/joshuayoung/Projects/puma/test/helpers/integration.rb:392:in `block (3 levels) in hot_restart_does_not_drop_connections'
        from /Users/joshuayoung/Projects/puma/test/helpers/integration.rb:389:in `times'
        from /Users/joshuayoung/Projects/puma/test/helpers/integration.rb:389:in `block (2 levels) in hot_restart_does_not_drop_connections'