Add runs-on back

FranzBusch · thomasvl · commit df9d3159f431 · 2022-07-18T09:36:08.000-04:00
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -11,6 +11,7 @@ on:
 
 jobs:
   core:
+    runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
       matrix:
