Setup mailman3 server

We want to migrate to mailman3 as mailman2 is basically unmaintained and requires Python 2 which is EOL.

Because the mailman and mailman3 packages conflict and we don't want to perform a big bang migration, mailman3 must be deployed on a separate server. mailman-web (mailman3's web interface) hasn't been packaged yet, so for now we are using my homebrewed PKGBUILD.

[1] https://gist.github.com/klausenbusk/5982063f95c503754a51ed2fefb8915e

Ref #59 (closed)

---

Migrated lists:

• arch-announce
• arch-devops-private
• arch-events
• arch-wiki-admins

misc/get_key.py

@@ -40,10 +40,9 @@ with chdir(root):
 
 
 def load_vault(path):
-    with chdir(root):
-        return yaml.load(
-            vault_lib.decrypt(Path(path).read_text()), Loader=yaml.SafeLoader
-        )
+    return yaml.load(
+        vault_lib.decrypt(Path(path).read_text()), Loader=yaml.SafeLoader
+    )
 
 
 class OutputFormat(str, Enum):