Centralize GitHub Workflow groups declaration (#272)

It may not be the best place for that (gha.py would have been better), but it's the shorter / faster way to do it for now.

Moreover it now uses logging for writing the group. The logger format has been updated for this to work. This was done to fix issues on GitHub Action logs, where groups were declared after the logs.

src/sles.py

@@ -4,7 +4,6 @@ from bs4 import BeautifulSoup
 from common import dates, endoflife, http
 
 product = endoflife.Product("sles")
-print(f"::group::{product.name}")
 response = http.fetch_url("https://www.suse.com/lifecycle")
 soup = BeautifulSoup(response.text, features="html5lib")
 
@@ -31,4 +30,3 @@ for detail_id in [f"detail{row['id']}" for row in sles_header_rows]:
             logging.info(f"Ignoring {version}: date '{date_str}' could not be parsed")
 
 product.write()
-print("::endgroup::")