On Ubuntu Impish (development version), we're currently facing a
problem where thin's testsuite fails when it runs on an armhf system.
After some investigation, I noticed that the reason for this failure
was that the server was still running even after the loop on
spec/spec_helper.rb:stop_server.

Given that the loop is actively checking to see if the server has
stopped, I'd like to propose that the timeout be increased from 1
second to 10 seconds.  Although I'm not a fan of the
"let's-just-increase-the-timeout" type of solutions, in this
particular case I think it's justified and makes sense (1 second may
indeed be too quick for the server to properly stop).

Signed-off-by: Sergio Durigan Junior <sergio.durigan@canonical.com>

Fix a typo

* `File.exists?` is removed in ruby 3.2

* Fix deprecated rspec expectation syntax

* Fix `Socket.gethostbyname` deprecation

* Test on ruby 3.2 and rack 2.