Fix apt cache permission error

Cache only /var/cache/apt/archives instead of /var/cache/apt to avoid
permission errors with lock files and partial directories. The archives
directory contains the downloaded .deb packages and doesn't require
root permissions to cache.

Author: zph

.github/workflows/main.yml

@@ -147,7 +147,7 @@ jobs:
       - name: Cache apt packages
         uses: actions/cache@v4
         with:
-          path: /var/cache/apt
+          path: /var/cache/apt/archives
           key: ${{ runner.os }}-apt-${{ hashFiles('**/.github/workflows/main.yml') }}
           restore-keys: |
             ${{ runner.os }}-apt-