Remove Deno Deploy GitHub Actions workflow

Deleted the .github/workflows/functions-dn.yml file, removing the workflow for deploying to Deno Deploy. This may be due to a change in deployment strategy or deprecation of this workflow.

.github/workflows/functions-dn.yml

@@ -1,44 +0,0 @@
-name: Deploy to Deno Deploy
-
-on:
-  workflow_run:
-    workflows: ["Sync to Pages and Functions"]
-    types:
-      - completed
-    branches:
-      - main
-  workflow_dispatch:
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: false
-
-jobs:
-  deploy:
-    runs-on: ubuntu-latest
-    timeout-minutes: 15
-    permissions:
-      id-token: write
-      contents: read
-    if: ${{ github.event.workflow_run.conclusion == 'success' || github.event_name == 'workflow_dispatch' }}
-
-    steps:
-      - name: Checkout functions branch
-        uses: actions/checkout@v6
-        with:
-          ref: functions
-
-      - name: Setup Deno
-        uses: denoland/setup-deno@v2
-        with:
-          deno-version: v2.x
-
-      - name: Verify Deno installation
-        run: deno --version
-
-      - name: Deploy to Deno Deploy
-        uses: denoland/deployctl@v1
-        with:
-          project: xget
-          entrypoint: deno.js
-          root: .