Remove the Hydra status check workflow

I'm sick of receiving an email about this every 30 minutes.

.github/workflows/hydra_status.yml

@@ -1,20 +0,0 @@
-name: Hydra status
-
-permissions: read-all
-
-on:
-  schedule:
-    - cron: "12,42 * * * *"
-  workflow_dispatch:
-
-jobs:
-  check_hydra_status:
-    name: Check Hydra status
-    if: github.repository_owner == 'NixOS'
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v4
-      with:
-        fetch-depth: 0
-    - run: bash scripts/check-hydra-status.sh
-