use apt cache

.github/workflows/xahau-ga-nix.yml

@@ -174,6 +174,21 @@ jobs:
           with open(os.environ['GITHUB_OUTPUT'], 'a') as f:
               f.write(f"matrix={output}\n")
 
+  apt-cache:
+    runs-on: [self-hosted, generic, 20.04]
+    container:
+      image: ubuntu:24.04
+      volumes:
+        - /home/runner/.apt-cache:/var/cache/apt
+    steps:
+      - name: Install build dependencies to save apt cache
+        run: |
+          apt-get update
+          apt-get install -y software-properties-common
+          add-apt-repository ppa:ubuntu-toolchain-r/test -y
+          apt-get update
+          apt-get install -y python3 python-is-python3 pipx cmake ninja-build ccache perl libsqlite3-dev
+
   build:
     needs: matrix-setup
     runs-on: [self-hosted, generic, 20.04]
@@ -183,6 +198,8 @@ jobs:
         - /home/runner/.conan-cache:/.conan-cache
         - /home/runner/.ccache-main:/github/home/.ccache-main
         - /home/runner/.ccache-current:/github/home/.ccache-current
+        # apt cache as readonly
+        - /home/runner/.apt-cache:/var/cache/apt:ro
     defaults:
       run:
         shell: bash
@@ -202,6 +219,7 @@ jobs:
 
       - name: Install build dependencies
         run: |
+          # install dependencies from apt cache
           apt-get update
           apt-get install -y software-properties-common
           add-apt-repository ppa:ubuntu-toolchain-r/test -y