Bump to Ruby 3.2.3

[huwd]

Note ruby v3.0.0 is currently out but there's been some reported problems running it within Apple Silicone due to some changes at the C library level.

For now doing a cautious upgrade until we've confirmed we're unblocked on the mac / docker / ruby combo.

See: govuk-one-login/tech-docs#165

[lfdebrux]

I tested bundle exec middleman server with this branch on my machine, it worked but I did see this error:

~/.rbenv/versions/3.2.3/lib/ruby/gems/3.2.0/gems/tilt-2.0.11/lib/tilt/redcarpet.rb:64: warning: undefining the allocator of T_DATA class Redcarpet::Markdown

This appears to be a known and fixed issue with RedCarpet and Ruby 3.2 https://www.redmine.org/issues/38118, it might be worth also bumping RedCarpet in this PR?

[huwd]

huh, let me check if I can reproduce.
I'd thought as build and test went OK we were safe 🤔

No good if this blows up the local dev solution too

[huwd]

redcarpet is a dependency within the govuk_tech_docs 😭 really have to do an update over there at some point soon...

🤔 we could try and force it in the gemfile.lock... will take a look but not sure that's right vs trying to update it at source?

[huwd]

I wonder if the time has come to bite the bullet over here...
alphagov/tech-docs-gem#348

Might do a round of dep updates?

[DavidBiddle]

@huwd looks like tech-docs-gem has updated redcarpet, does that change anything for this PR?

[DavidBiddle]

Seems to build locally without any problems now so I'm happy to approve