In order to allow any of the maintainers to cut releases for runc,
create a keyring file that distributions can use to verify that releases
are signed by one of the maintainers.
The format matches the gpg-offline format used by openSUSE packaging,
but it can be easily imported with "gpg --import" so any distribution
should be able to handle this keyring format wtihout issues.
Each key includes the GitHub handle of the associated user. There isn't
any way for this information to be automatically verified (outside of
using something like keybase.io) but since all changes of this file need
to be approved by maintainers this is okay for now.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
