ci: add docker publish dry-run

Author: PierreJeanjacquot

.github/workflows/pr-test.yml

@@ -71,5 +71,13 @@ jobs:
       - name: Build
         run: npm run build
 
-      - name: publish dry-run
+      - name: npm publish dry-run
         run: npm publish --dry-run
+      
+      - name: docker publish dry-run
+        uses: iExecBlockchainComputing/github-actions-workflows/[email protected]
+        with:
+          push: false
+          image-name: 'iexechub/iexec-sdk'
+          dockerfile: 'Dockerfile'
+          context: '.'