Freeze Jakarta (and what remained of Ithaca)

Context

This MR removes executables, tests, and lib_delegate for Jakarta. And for Ithaca, because only parts of the tests were removed for Ithaca.

Manually testing the MR

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Checklist

• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR