.github/workflows/pack.yml: Update runner to ubuntu-latest.

Author: TxGVNN

.github/workflows/pack.yml

@@ -13,7 +13,7 @@ permissions:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
       with: