Summarized changelog:
- add more tests for CVE-2021-23980
- update vendorverify script to detect and fail when extra files are vendored
- clean escapes HTML comments even when strip_comments=False
- fix clean and linkify raising ValueErrors for certain inputs.
- Migrate CI to Github Actions.
- fix linkify raising an IndexError on certain inputs.
Packager notes:
Enable build test. Failing tests are an upstream bug with python 3.9.
Reference task T9866
Signed-off-by: Algent Albrahimi <algent@protonmail.com>