Bump base image to Ruby 3.4.9 / Alpine 3.24

[DavidBiddle]

What problem does this pull request solve?

Bumps core dependencies and base image in Dockerfile.

• Bumps Ruby from 3.4.8 to 3.4.9
• Bumps Node.js from 22.16.0 to 24.17.0
• Bumps Alpine Linux from 3.22 to 3.24

Things to consider when reviewing

• Ensure that you consider the wider context.
• Does it work when run on your machine?
• Is it clear what the code is doing?
• Do the commit messages explain why the changes were made?
• Are there all the unit tests needed?
• Do the end to end tests need updating before these changes will pass?
• Has all relevant documentation been updated?

[github-actions]

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