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/redhat_lifecycles.py

@@ -1,7 +1,7 @@
 import logging
 import urllib.parse
 
-from common import dates, endoflife, http, releasedata
+from common import dates, http, releasedata
 
 """Fetches EOL dates from the Red Hat Product Life Cycle Data API.
 
@@ -17,7 +17,7 @@ class Mapping:
     def get_field_for(self, phase_name: str) -> str | None:
         return self.fields_by_phase.get(phase_name.lower(), None)
 
-for config in endoflife.list_configs_from_argv():
+for config in releasedata.list_configs_from_argv():
     with releasedata.ProductData(config.product) as product_data:
         name = urllib.parse.quote(config.url)
         mapping = Mapping(config.data["fields"])