chore(renovate): remove unused TEAMS_WEBHOOK env - notifications via Gitea webhook

.woodpecker/renovate.yml

@@ -15,6 +15,7 @@
 #
 # This pipeline ONLY runs on the "renovate" cron schedule.
 # It does NOT run on push events - that is handled by .woodpecker.yml
+# Teams notifications are delivered via Gitea webhook → Power Automate
 # ================================================================
 
 when:
@@ -39,8 +40,5 @@ steps:
       # Use the renovate.json in the repo root for all other config
       RENOVATE_CONFIG_FILE: renovate.json
       LOG_LEVEL: info
-      # MS Teams Power Automate webhook - used by postUpgradeTasks in renovate.json
-      TEAMS_WEBHOOK:
-        from_secret: teams_webhook_renovate
     commands:
       - renovate