Remove sign-addon dependency

[willdurand]

Once we make the submission API the default, we can remove sign-addon and the old signing code.

[lsim]

Any thoughts on when this task might get released? It's tripping up my CI audit.

[ioanarusiczki]

@willdurand

I uploaded using web-ext 7.8.0 listed and unlisted versions

on AMO Dev: https://addons-dev.allizom.org/en-US/developers/addon/38a04afb6f9f4ed39123/versions
on AMO Stage: https://addons.allizom.org/en-US/developers/addon/web-ext-submission-on-amode2/versions

During the process I don't think I've noticed changes. I did have errors after the upload when I did not add metadata for listed versions in metadata.json, but I'm sure that's expected to happen.

When I'm at the signing step, I exit it with Ctrl+C , this would be the last step of the web-ext submission:

[willdurand]

I guess we're good then?

[ioanarusiczki]

@willdurand Yes, I really wish I had more time to explore but there's too many issues on the other repos.

Marking this verified.