Ensure Python binary used by Poetry is consistent post-install

[eramongodb]

A minor improvement to the poetry.sh script that works around unintuitive Poetry Python binary selection behavior post-install. The venv created by Poetry doesn't always use the correct Python binary post-install, even if a specific Python binary was used to run the install script. See the linked PR in the comment for further details.

The separate call to with-lock makes me frown, but I could not find a straightforward solution to combine both the Poetry install and run commands, as with-lock does not support using shell functions as the executed command, and Poetry itself doesn't support specifying the Python binary in the install command (user requests for --python <path/to/python> seem to have been rejected; see linked PR). I don't think this will cause issues in practice (it's not that likely that we run into a race condition here), so proposed as-is, but if there's a more elegant solution here that I missed, I'd be happy to apply it.

[vector-of-bool]

This is almost correct, but will probably break subtly in the future. See comment for details.