Summary

Update the devcontainer Dockerfile so that it works with Node.js 20 and the project's expected version of yarn.

Test instructions | Instructions pour tester la modification

Open the project in a devcontainer and expect it to complete with no errors.

n/a

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[x] Have you completely tested the functionality of change introduced in this PR? Is the PR solving the problem it's meant to solve within the scope of the related issue?
[x] The PR does not introduce any new issues such as failed tests, console warnings or new bugs.
[ ] If this PR adds a package have you ensured its licensed correctly and does not add additional security issues?
[x] Is the code clean, readable and maintainable? Is it easy to understand and comprehend.
[x] Does your code have adequate comprehensible comments? Do new functions have docstrings?
[ ] Have you modified the change log and updated any relevant documentation?
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