Add GHA workflow to upload kickstart script to our repo server. (#16724)

This will be used for hosting of the script going forwards. Further
changes will need to happen on the system itself to put the script in
the right place and ensure it gets served properly.

.github/workflows/kickstart-upload.yml

@@ -0,0 +1,54 @@
+---
+# Upload the kickstart script to the repo server
+name: Upload Kickstart Script
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - .github/workflows/kickstart-upload.yml
+      - packaging/installer/kickstart.sh
+  workflow_dispatch: null
+concurrency:
+  group: kickstart-upload
+  cancel-in-progress: true
+jobs:
+  upload:
+    name: Upload Kickstart Script
+    runs-on: ubuntu-latest
+    if: github.repository == 'netdata/netdata'
+    steps:
+      - name: Checkout
+        id: checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+      - name: SSH setup
+        id: ssh-setup
+        uses: shimataro/ssh-key-action@v2
+        with:
+          key: ${{ secrets.NETDATABOT_PACKAGES_SSH_KEY }}
+          name: id_ecdsa
+          known_hosts: ${{ secrets.PACKAGES_KNOWN_HOSTS }}
+      - name: Upload
+        id: upload
+        run: rsync -vp packaging/installer/kickstart.sh netdatabot@packages.netdata.cloud:/home/netdatabot/incoming/kickstart.sh
+      - name: Failure Notification
+        uses: rtCamp/action-slack-notify@v2
+        env:
+          SLACK_COLOR: 'danger'
+          SLACK_ICON_EMOJI: ':github-actions:'
+          SLACK_TITLE: 'Kickstart upload failed:'
+          SLACK_USERNAME: 'GitHub Actions'
+          SLACK_MESSAGE: |-
+              ${{ github.repository }}: Failed to upload updated kickstart script to repo server.
+              Checkout: ${{ steps.checkout.outcome }}
+              Import SSH Key: ${{ steps.ssh-setup.outcome }}
+              Upload: ${{ steps.upload.outcome }}
+          SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: >-
+          ${{
+            failure()
+            && startsWith(github.ref, 'refs/heads/master')
+            && github.repository == 'netdata/netdata'
+          }}