nixosTests/pleroma: fix test
Two issues:
1. We need a subjectAltName on the TLS cert. Stolen from the akkoma
test. <3 illdefined
2. There's a bug in the current toot release wrt. date parsing. It's
been fixed upstream but it's not been released yet. Using the
current toot master for this VM test to work around this.
Note: I warned upstream we'd need a new toot release.
Fixes https://github.com/NixOS/nixpkgs/issues/264951
authored by Félix Baylac Jacqué and committed by Yaya f80b2b51 c16a6fe2