chore(ci): faster build

Signed-off-by: skjnldsv <skjnldsv@protonmail.com>

Author: skjnldsv

.github/workflows/sphinxbuild.yml

@@ -58,11 +58,25 @@ jobs:
     - name: Checkout repository
       uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
+    - name: Allow apt cache write access for caching
+      if: ${{ matrix.manual.build_pdf_path }}
+      run: sudo chmod -R a+rw /var/cache/apt/archives
+
+    - name: Cache LaTeX apt packages
+      if: ${{ matrix.manual.build_pdf_path }}
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
+      with:
+        path: /var/cache/apt/archives
+        key: latex-apt-${{ runner.os }}-${{ hashFiles('.github/workflows/sphinxbuild.yml') }}
+        restore-keys: |
+          latex-apt-${{ runner.os }}-
+
     - name: Install LaTeX dependencies
       if: ${{ matrix.manual.build_pdf_path }}
       run: |
         sudo DEBIAN_FRONTEND=noninteractive apt-get update
         sudo DEBIAN_FRONTEND=noninteractive apt-get install -y \
+          --no-install-recommends \
           python3-pil \
           python3-pip \
           texlive-fonts-recommended \