refactor(ops/machines): switch from grafana-agent to alloy

grafana-agent has been removed, but the failing eval was missed due
to #80.

Change-Id: I87cfc71c8c98e27e32f4e95e4d85901195cb5b75
Reviewed-on: https://cl.snix.dev/c/snix/+/30347
Autosubmit: Florian Klink <flokli@flokli.de>
Reviewed-by: Ryan Lahfa <masterancpp@gmail.com>
Tested-by: besadii

ops/machines/build01/default.nix

@@ -5,7 +5,7 @@ let
 in
 {
   imports = [
-    (mod "o11y/agent.nix")
+    (mod "o11y/alloy.nix")
     (mod "snix-buildkite.nix")
     (mod "harmonia.nix")
     (mod "known-hosts.nix")

ops/machines/gerrit01/default.nix

@@ -10,7 +10,7 @@ in
 
     (mod "hetzner-cloud.nix")
     (mod "restic.nix")
-    (mod "o11y/agent.nix")
+    (mod "o11y/alloy.nix")
     (mod "gerrit-autosubmit.nix")
     (mod "monorepo-gerrit.nix")
     (mod "www/cl.snix.dev.nix")

ops/machines/meta01/default.nix

@@ -9,7 +9,7 @@ in
     ./disko.nix
 
     (mod "hetzner-cloud.nix")
-    (mod "o11y/agent.nix")
+    (mod "o11y/alloy.nix")
     (mod "o11y/mimir.nix")
     (mod "o11y/loki.nix")
     (mod "o11y/tempo.nix")

ops/machines/public01/default.nix

@@ -12,7 +12,7 @@ in
     (mod "forgejo.nix")
     (mod "restic.nix")
     # Automatically enable metric and log collection.
-    (mod "o11y/agent.nix")
+    (mod "o11y/alloy.nix")
     (mod "o11y/grafana.nix")
     (mod "www/snix.dev.nix")
     (mod "www/bolt.snix.dev.nix")