fix(startup): create config directory before singleton lock (#242)

.github/workflows/quality-gate.yml

@@ -60,8 +60,11 @@ jobs:
 
       - name: Install Lua
         run: |
-          sudo apt-get update
-          sudo apt-get install -y lua5.4
+          # Lua needs only Ubuntu sources; unrelated runner repositories can be unavailable.
+          test -f /etc/apt/sources.list.d/ubuntu.sources
+          apt_sources=(-o Dir::Etc::sourcelist=sources.list.d/ubuntu.sources -o Dir::Etc::sourceparts=-)
+          sudo apt-get "${apt_sources[@]}" update
+          sudo apt-get "${apt_sources[@]}" install -y lua5.4
           sudo ln -sf /usr/bin/lua5.4 /usr/local/bin/lua
           lua -v