This ensures to use the correct python executable.
Using `run` simply uses `sys.prefix` with a bin suffix, which is not necessarily the currently used python executable.

E.g. when linking a specific python version to a custom directory, using `sys.prefix` may point to the wrong python version:
* /usr/bin/python2.7
* /usr/bin/python3.6
* /usr/bin/python is a symlink to 2.7
* /usr/bin/local/python (or any other location) is a symlink to 3.6 which shadows the former symlink
`sys.prefix` is `/usr` in this case, which is correct, but the `python` executable there points to the wrong version.

`run_pip` in the env fixes this already by using `sys.executable`, see https://github.com/python-poetry/poetry/blob/develop/poetry/utils/env.py#L964
This should be used in the executor as well.

…istage

…istage

…idebar by the framework

…a/poetry into docs/docker-best-practices

…y-multistage

As suggested in https://github.com/orgs/python-poetry/discussions/1879#discussioncomment-10923546

…tall --no-root'

Edit Dockerfile as suggested in
- python-poetry#9542 (comment)
- python-poetry#9542 (comment)

Edit Dockerfile as suggested in
- python-poetry#9542 (comment)