monitoring: disable radarr exporter (version mismatch)

Radarr on TrueNAS jail is too old - exportarr fails on
/api/v3/wanted/cutoff endpoint (404). Keep sonarr which works.

Vault secret kept for when Radarr is updated.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

services/monitoring/exportarr.nix

@@ -1,26 +1,12 @@
 { config, ... }:
 {
-  # Vault secrets for API keys
+  # Vault secret for API key
-  vault.secrets.radarr-api-key = {
-    secretPath = "services/exportarr/radarr";
-    extractKey = "api_key";
-    services = [ "prometheus-exportarr-radarr-exporter" ];
-  };
-
   vault.secrets.sonarr-api-key = {
     secretPath = "services/exportarr/sonarr";
     extractKey = "api_key";
     services = [ "prometheus-exportarr-sonarr-exporter" ];
   };
 
-  # Radarr exporter
-  services.prometheus.exporters.exportarr-radarr = {
-    enable = true;
-    url = "http://radarr-jail.home.2rjus.net:7878";
-    apiKeyFile = config.vault.secrets.radarr-api-key.outputDir;
-    port = 9708;
-  };
-
   # Sonarr exporter
   services.prometheus.exporters.exportarr-sonarr = {
     enable = true;
@@ -29,14 +15,8 @@
     port = 9709;
   };
 
-  # Scrape configs
+  # Scrape config
   services.prometheus.scrapeConfigs = [
-    {
-      job_name = "radarr";
-      static_configs = [{
-        targets = [ "localhost:9708" ];
-      }];
-    }
     {
       job_name = "sonarr";
       static_configs = [{