Copy entry points and Jupyter data directories into ephemeral environments (#14790)
This is an alternative to https://github.com/astral-sh/uv/pull/14788
which has the benefit that it addresses
https://github.com/astral-sh/uv/issues/13327 which would be an issue
even if we reverted #14447.
There are two changes here
1. We copy entry points into the ephemeral environment, and rewrite
their shebangs (or trampoline target) to ensure the ephemeral
environment is not bypassed.
2. We link `etc/jupyter` and `share/jupyter` data directories into the
ephemeral environment, this is in order to ensure the above doesn't
break Jupyter which unfortunately cannot find the `share` directory
otherwise. I'd love not to do this, as it seems brittle and we don't
have a motivating use-case beyond Jupyter. I've opened
https://github.com/jupyterlab/jupyterlab/issues/17716 upstream for
discussion, as there is a viable patch that could be made upstream to
resolve the problem. I've limited the fix to Jupyter directories so we
can remove it without breakage.
Closes https://github.com/astral-sh/uv/issues/14729
Closes https://github.com/astral-sh/uv/issues/13327
Closes https://github.com/astral-sh/uv/issues/14749
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Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>