Yarn 4 + ESLint 9 + PnP Support (3)

[SleeplessByte]

It keeps breaking on GH (probably the diff) so just recreating as that seems to trigger a working CI once.

• Upgrade to Yarn 4, ESLint 9, and add PnP support
• Upgrade SDKs
• Sync
• Format files
• Fix .vscode files, upgrade all tests to new format
• Update workflows to Node LTS @ 20
• Fix lint issues
• Remove babel transpilation for common actions
• Simplify changed files check

[github-actions]

This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.

If this PR does not affect the result of the test (or, for example, adds an edge case that is not worth rerunning all tests for), please add the following to the merge-commit message which will stops student's tests from re-running. Please copy-paste to avoid typos.

[no important files changed]

For more information, refer to the documentation. If you are unsure whether to add the message or not, please ping @exercism/maintainers-admin in a comment. Thank you!

[SleeplessByte]

(Please do not merge yet, test-runner needs to be updated first)

[ErikSchierboom]

I'm sure you noticed, but please merge this with [no important files changed] in the commit message.

[SleeplessByte]

@ErikSchierboom no let's rerun the tests on EVERY SINGLE SOLUTION :') /s

Technically [no important files changed] is even correct as none of the tests or content has changed.