Fix release workflows. (#229)

- Trigger dockers on release.
- Update ruby setup for deb-s3.

Author: yossigo

.github/workflows/dockers.yml

@@ -9,6 +9,8 @@ on:
       - master
 
   workflow_dispatch:
+  release:
+    types: [published]
 
 jobs:
 

.github/workflows/release.yml

@@ -132,7 +132,7 @@ jobs:
     - name: Get binary packages
       uses: actions/download-artifact@v2
     - name: Setup ruby
-      uses: actions/setup-ruby@v1
+      uses: ruby/setup-ruby@v1
       with:
           ruby-version: "2.7"
     - name: Install deb-s3