Revert "Update synchronize-launchpad.yml"

This reverts commit 131e363.

Author: Flamefire

.github/workflows/synchronize-launchpad.yml

@@ -12,6 +12,7 @@ on:
 jobs:
   upload:
     runs-on: ubuntu-latest
+    container: 'ubuntu:18.04'
     steps:
       - name: Install dependencies
         run: |