update platform from ubuntu-20.04 to ubuntu-latest (#90)

Author: deniak

.github/workflows/auto-publish.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   main:
     name: Echidna Auto-publish WD
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
         with: