this is in response to
https://github.com/certbot/certbot/pull/10399#issuecomment-3166305086
this PR does two things:
1. it clarifies what is meant by "build dependencies" in DESIGN.md
2. fixes our workaround for
https://github.com/python-poetry/poetry/issues/4103 which broke when we
moved most of our code under `src` directories. i kept the previous `rm
-rf ${REPO_ROOT}/*/*.egg-info` line around for `letstest` and to
hopefully add some robustness for us if we ever move our code around
again
this PR hopefully improves two things that i hit while working on #10035
1) i found that repinning our dependencies took ~6 minutes!
digging into it a bit, the biggest culprit i found was the inclusion of
`--no-cache-dir` here which seemed to cause poetry to redownload the
same packages over and over in a single run. this comes from
https://github.com/certbot/certbot/pull/9453 which fixed a problem i
(but not alex) was having with a major performance penalty. i removed
the flag here and instead included instructions on clearing poetry's
caches in case anyone ever hits this in the future. with this change,
the script now takes about 40 seconds on my laptop
2) every run of this script ended with the output:
```
Warning: poetry-plugin-export will not be installed by default in a
future version of Poetry.
In order to avoid a breaking change and make your automation
forward-compatible, please install poetry-plugin-export.
explicitly. See https://python-poetry.org/docs/plugins/#using-plugins
for details on how to install a plugin.
To disable this warning run 'poetry config warnings.export false'.
```
setting `POETRY_WARNINGS_EXPORT=false` fixes this which i believe is
safe to do because of
https://github.com/certbot/certbot/blob/2c8609464c3e371053f78e515fc7beb26446f5a3/certbot/setup.py#L53-L56
