Cache apt packages (#7978)

* Cache apt packages

* Match apt cache key with OS version

That way it's easier to remember updating the key when the OS version is changed.

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ permissions:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         doc-type: ['HTML', 'EPUB', 'PDF']
@@ -33,10 +33,10 @@ jobs:
         python -m pip install --upgrade pip
         pip install -r requirements.txt
 
-    - name: Install packages
-      run: |
-        sudo apt update
-        sudo apt install texlive-latex-recommended texlive-latex-extra texlive-fonts-recommended texlive-lang-all
+    - uses: awalsh128/cache-apt-pkgs-action@v1
+      with:
+        packages: texlive-latex-recommended texlive-latex-extra texlive-fonts-recommended texlive-lang-all
+        version: ubuntu-24.04
 
     - name: Build Docs
       run: |