Update GitHub Actions workflow to use 'pdf-without-images' target for PDF generation

Author: gocs

.github/workflows/publish.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v2
       - name: Set tag release as environment variable
         run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
-      - name: Step 0- Build glslviewer
+      - name: Step 0 - Build glslviewer
         run: |
             # Install glslviewer
             sudo apt-get update && sudo apt-get install git build-essential cmake xorg-dev libglu1-mesa-dev libncurses5-dev libncursesw5-dev \
@@ -40,7 +40,7 @@ jobs:
             /sbin/start-stop-daemon --start --quiet --pidfile /tmp/custom_xvfb_99.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :99 -screen 0 1920x1200x24 -ac +extension GLX
             sudo apt-get install texlive-xetex pandoc python3
       - name: Step 2 - Build book.pdf
-        run: make pdf
+        run: make pdf-without-images
       - name: Step 3 - Append version to book.pdf
         run: |
             mkdir release