refactor(setup): use pipx for Ansible to avoid conflicts between pip and apt packages

[kenji-miyake]

Description

Installing ansible via pip can conflict with some apt packages.

$ docker run --rm -it ubuntu:20.04 /bin/bash
$ apt update && DEBIAN_FRONTEND=noninteractive apt -y install python3-flask && apt -y install python3-pip && pip install ansible
$ python3
>>> import flask
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/flask/__init__.py", line 14, in <module>
    from jinja2 import escape
ImportError: cannot import name 'escape' from 'jinja2' (/usr/local/lib/python3.8/dist-packages/jinja2/__init__.py)

Also previously, there was a similar error.
#2849

To avoid these kinds of errors, I'd like to use pipx instead, which can create a virtual environment for application packages.

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[wep21]

LGTM