Refactor scripts arguments handling (#456)

- remove the use of environment variables to get directory paths,
- make use of arguments / argparse instead of environment variables in `update.py` and `report.py`,
- automatically guess the data directory in `latest.py` based on the script's location,
- propagate log level to auto scripts,
- move `list_configs_from_argv` from `endoflife` module to `releasedata` module,
- use `list_products` in `latest.py` to load the product's frontmatters.

src/chef-inspec.py

@@ -1,4 +1,4 @@
-from common import dates, endoflife, github, http, releasedata
+from common import dates, github, http, releasedata
 
 """Fetch released versions from docs.chef.io and retrieve their date from GitHub.
 docs.chef.io needs to be scraped because not all tagged versions are actually released.
@@ -6,7 +6,7 @@ docs.chef.io needs to be scraped because not all tagged versions are actually re
 More context on https://github.com/endoflife-date/endoflife.date/pull/4425#discussion_r1447932411.
 """
 
-for config in endoflife.list_configs_from_argv():
+for config in releasedata.list_configs_from_argv():
     with releasedata.ProductData(config.product) as product_data:
         html = http.fetch_html(config.url)
         released_versions = [h2.get('id') for h2 in html.find_all('h2', id=True) if h2.get('id')]