changes to ci

.github/workflows/build-debian-image-beta.yml

@@ -1,25 +1,23 @@
 # Github action to build Docker image from beta branch (tag: beta)
-name: Build debian based image (beta)
+name: Build image (buanet/iobroker:beta)
 
 on:
-  workflow_dispatch:
-  pull_request:
-    branches:
-      - beta
+  release:
     types:
-      - closed
-  schedule:
-    - cron: '42 3 * * 1'
+      - prereleased
 
 jobs:
-  bulid-beta-image:
+  build-beta-image:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout repo (beta)
+      - name: Getting published prerelease tag
+        run: echo "RELEASE_TAG=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+    
+      - name: Checkout repo
         uses: actions/checkout@v2.4.0
         with:
           repository: 'buanet/ioBroker.docker'
-          ref: 'beta'
+          ref: ${{ env.RELEASE_TAG }}
 
       - name: Get and write version and date
         id: version