refactor(ops): Move irccat secret into agenix

The irccat module uses DynamicUser, so to grant permission to it a new
group has been added for irccat.

I have some vague memory of DynamicUser + Group not behaving as one
would expect, but we'll see what happens.

Change-Id: Iab9f6a3f1a53c4133b635458ce173250cc9a3fac

ops/secrets/irccat.age

@@ -0,0 +1,11 @@
+age-encryption.org/v1
+-> ssh-ed25519 dcsaLw WeT9p0wllWBLB6/RaTgrGO4ubKl3suTC483oBX8Jsh0
+IwLXJUlKavRabns7qiqE8TphNngbNxNvvCOpJXFV6Qs
+-> ssh-ed25519 OkGqLg +yCpWW0lv9Isk1CYcK/sJijyq+mxNXgVXG0J75vZ4F0
+mru1AKnleSb5r+CjB5+jvyC3rRGVF54Q0N4rZHkQsjY
+-> _h3i%-grease {3x|6wy X&)#|/^
+NMjmXcjJYfi/B3gloItYOFPGl5OHQJRBX0UruGbC5UZUeQDDPWMqRfrSZpiWFYzJ
+iDikRO3KSTQBeL+OHHZakQvQVC5rt0zQnC+HIA
+--- VZ+e0jdAd2a6fp9OtJQiNageeAqbAwkHDBDujgXx/aY
+-a~ª…%UG´Á†v€*"F˜
+ìã<öNÚ‡¹qîÛ7/ÚcÜKhP‘S—Ðy¢<]VÝ*ÖZhõ8Jq«0ôŠÛФ÷'­oÊÛ¥æ3Ó\®zêSÝ–¢ÎuEµ-©'Nï`M

ops/secrets/secrets.nix

@@ -10,8 +10,9 @@ let
 in {
   "besadii.age" = default;
   "buildkite-agent-token.age" = default;
-  "clbot.age" = default;
   "clbot-ssh.age" = default;
+  "clbot.age" = default;
   "gerrit-queue.age" = default;
+  "irccat.age" = default;
   "owothia.age" = default;
 }