This should finally elimate the painful manual exports from
~/.asdf/asdf.sh file after initing submodules post-clone.
Also in this commit, I also edited the sign-tarball script to
not hardcode the GPG key ID when signing. I may implement CLI
flags in the future as needed.
Signed-off-by: Andrei Jiroh Halili <ajhalili2006@andreijiroh.xyz>