Update unicode and roc-parser packages, and the basic-cli platform

[ageron]

This PR updates the unicode library to 4.2.0. The new API uses Grapheme.split instead of Grapheme.owned.
This requires first updating the roc-test-runner to ensure the library is available (since test runners don't have internet access).

Edit: the PR now updates the roc-parser package and the basic-cli platform as well, and it adds a bin/sync-roc-dependencies.sh script which looks at the given URL or filepath to the roc-test-runner's bin/download-dependencies.roc file and updates the Roc track to use the same package & platform versions.

Note: It's important for the Roc track to be in sync with the roc-test-runner because when the exercise solutions are tested by the roc-test-runner, they don't have internet access and must rely on the cached packages and platforms downloaded by bin/download-dependencies.roc when the docker container is created.

[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!