Try to fix runs-on default

.github/workflows/build-images.yaml

@@ -20,7 +20,7 @@ on:
       type:
         description: 'runner?'
         required: false
-        default: 'ubuntu-latest'        
+        default: 'ubuntu-latest'
   schedule:
    - cron: '0 1 * * *'
 
@@ -32,7 +32,7 @@ name: Builds and pushes tagged image to DockerHub
 jobs:
   generate_build_deps:
     name: Generate Build Deps
-    runs-on: ${{ github.event.inputs.type }}    
+    runs-on: ${{ fromJSON('["ubuntu-latest", github.event.inputs.type]')[github.event.inputs.type == ''] }}
     steps:
       - name: Reclaiming disk space on / by removing dotnet/android/ghc
         if: ${{ github.event.inputs.type == 'ubuntu-latest' }}