[ECO-4688] Fix tests

[sacOO7]

• Add support for latest ruby versions 3.2 and 3.3
• Fixed failing test due to old simplecov dependency
• For more info => Calling Simplecov.start more than once raises an exception simplecov-ruby/simplecov#1003
• Fixed[ably-ruby] Fix failing tests #394

[umair-ably]

couple formatting issues - happy for these to be fixed in your upcoming PR if that's easier

[lawrence-forooghian]

I've left some comments (and agree with Umair re all the unnecessary formatting changes).

I’d also like to mention that I found this PR difficult to review — in my opinion, unnecessarily so. There weren't any instructions on how to review it, so I tried reviewing it commit by commit. Unfortunately, there are many commits which turn out to be reverted by later commits, meaning that reviewing those commits turned out to be a waste of my time. Furthermore, the motivation for some of the changes is not very obvious, and isn't explained in the commit message, meaning that I had to spend time trying to understand what your intention was. I worry that if such a small PR was quite hard to review, then some of your upcoming larger protocol v2 ones will be very hard to review. Please could I ask that you spend time on those PRs to consider the experience for somebody trying to review them?

[sacOO7]

Thanks for approval 👍