Preparing for the next minor Ruby version

[boardfish]

It seems as though the next Ruby version will default to string literals being frozen. The linked gist outlines some things we can add to CI to make sure we're not falling foul of this.

Depending on whether there are any violations or not, we could enforce it strictly or add it as a test matrix option that we don't require in order for CI to pass. Happy to pick this up myself in the near future.

[reeganviljoen]

@boardfish in #2030 I also noticed a tests that was failing because of mismatched regex/string encodings I wonder if this is a bug in ruby(no mention in https://bugs.ruby-lang.org/) or a breaking change, just thought its worth noting

[boardfish]

Interesting! Good to see that testing against Ruby head is proving itself useful already ✨

[reeganviljoen]

@boardfish I am seeing a lot of these warnings, what strategy do you think we should use to collect and diagnose which dependencies they are coming from

[reeganviljoen]

@boardfish I have been thinking about this, since the release is so nearby this is quite important now, maybe we could do a test run, with some kind of mechanism to catch any warnings against ruby main, then report any issues to our dependencies