Try to fix gh-pages workflow

Increased the retention period for GHA artifacts

.github/workflows/build.yml

@@ -59,4 +59,4 @@ jobs:
     with:
      name:           sfall-build
      path:           sfall-build
-     retention-days: 14
+     retention-days: 30

.github/workflows/gh-pages.yml

@@ -19,7 +19,7 @@ jobs:
 
       - name: Install dependencies
         run: |
-          sudo apt -y -qq install bundler python3-pip
+          sudo apt update && sudo apt -y -qq install bundler python3-pip
           pip3 install ruamel.yaml --user
 
       - name: Build