Merge pull request #8095 from nextcloud/assembleOnUbuntu

Assemble can run on ubuntu, so we save precious macOS testing time

.github/workflows/assembleFlavors.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
     flavor:
-        runs-on: macOS-latest
+        runs-on: ubuntu-latest
         strategy:
             fail-fast: false
             matrix: