Forge updates: patch archival, no more /allow and teams

Hi folks,
As those of you that are subscribed to gcc-patches already know by now, 
I've started sending closed forge pull requests to the mailing list for 
archival. There's more to come but I'm taking it easy because the email 
volume is creating issues with delivery.
I'm aware some of you may want to avoid these emails about old pull 
requests.
You can filter them using the "X-Mailer: batrachomyomachia" header. Read 
below however.

The mechanism and the emails are the same that you will see from now on 
for every pull request people create on 
https://forge.sourceware.org/gcc/gcc-TEST except that those emails will 
come more regularly (when there's a request to review, when someone 
reviews a patch, etc).

I'll reply to this email signaling the archival is complete and you'll 
be able to remove the filter then as this will allow you to keep up to 
date with patches coming from the forge.

If you're wondering how to use the forge, why not have a look at the 
https://gcc.gnu.org/wiki/UsingForge wiki page providing instructions? :)

New joiners will no longer have to be /allowed and the welcome message 
is now more terse.

Finally, I've updated the gcc org's teams in forgejo. These are currently:
- Collaborators: this is the team where people who don't have write 
after approval are added to. They can create a pull request but not make 
modifications to others.
- Write.After.Approval: people with write after approval access in 
MAINTAINERS file. They can make some changes to other's pull requests 
and forgejo actions runs.
- Reviewers: Reviewers in MAINTAINERS file. They have the same 
permissions as Write.After.Approval.
- Maintainers: this is a group that includes all maintainers (including 
global).
- Maintainers.Algol68: group for people with administrator access to the 
gcc-a68 repository
- Maintainers.Global: Global Reviewers in MAINTAINERS file. They have 
full write access to the repository, issues, pull requests, wiki, 
projects (if they were enabled)
- Release.Managers: what it says
- Automation: this is for bots, currently the forgejo bot can push 
changes to the repository
- Owners: these people have admin rights that allow them to change the 
gcc organisation's teams and its composition. They have effectively full 
write access.

Please let us know if you face any issues with the forge, whether in 
using it or if the way it sends emails is not working for you, whether 
in the forge mailing list, the overseers channel, or just send me an email.

Happy Hacking!
Claudio