ci: remove deploy workflow, replaced by Watchtower

Auto-deploy is now handled by Watchtower on Unraid, which polls
for new images every 5 minutes for labeled containers.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/deploy.yml

@@ -1,16 +0,0 @@
-name: Deploy Nanobot
-
-on:
-  workflow_dispatch:
-
-jobs:
-  deploy:
-    runs-on: [self-hosted, linux-amd64]
-    timeout-minutes: 5
-    steps:
-      - name: Pull latest image and restart container
-        env:
-          UNRAID_PASS: ${{ secrets.UNRAID_PASS }}
-        run: |
-          sshpass -p "$UNRAID_PASS" ssh -o StrictHostKeyChecking=no -p 23 root@192.168.1.50 \
-            "docker pull git.wylab.me/wylab/nanobot:latest && docker restart nanobot"