Remove the WG private keys from the vault and store them only on the servers

With the support for network.wireguard.* credentials[1] in systemd v256[2], we can now easily avoid storing the credentials centrally in our ansible vault, which is preferable as it makes the private keys less exposed. It may also make fine-grained access easier in the future[3] as there is no longer a vault file for each server.

All the keys have been rotated and the new private keys are only stored on the servers.

[1] https://github.com/systemd/systemd/pull/30826 [2] https://github.com/systemd/systemd/releases/tag/v256 [3] #64

host_vars/repos.archlinux.org/misc.yml

@@ -14,4 +14,4 @@ system_disks:
 raid_level: "raid1"
 
 wireguard_address: 10.0.0.45
-wireguard_public_key: MDt3DqmYppnV81CFHLII1O80BWFGYeGGNrDWlQcX5H8=
+wireguard_public_key: ZE7fr78hG6eB3Qjhys0n7DxplMBbcWzBGI7DhMvCeDc=