Add secret detection

https://docs.gitlab.com/ee/user/application_security/secret_detection/pipeline/index.html

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/default.nix

@@ -68,7 +68,7 @@
       libraries = [ ];
     };
     ssh.knownHosts = {
-      eirene-vm.publicKeyFile = ../eirene/vm/secrets/ssh_host_ed25519_key.pub;
+      eirene.publicKeyFile = ../eirene/secrets/ssh_host_ed25519_key.pub;
     };
   };