Update links and references to github.com to git.vdb.to.
Also enable the flake8 lint action in gitea.
Reviewed-on: https://git.vdb.to/cerc-io/stack-orchestrator/pulls/732
Co-authored-by: Thomas E Lackey <telackey@bozemanpass.com>
Co-committed-by: Thomas E Lackey <telackey@bozemanpass.com>