Update publish-npm.yml

Update action to run on ubuntu-20.04, because the action started to fail using ubuntu-latest.

Author: pryhoda

.github/workflows/publish-npm.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3