ci: limit to 1 machine at all times

Author: barelyhuman

.github/workflows/fly-deploy.yml

@@ -11,6 +11,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: superfly/flyctl-actions/setup-flyctl@master
-      - run: flyctl deploy --remote-only
+      - run: flyctl deploy --remote-only --ha=false
         env:
           FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}