fix: Install complete build dependencies for sass-embedded

Add comprehensive system packages required for sass-embedded native extension:
- build-essential, gcc, g++, make: core build tools
- pkg-config: package configuration tool
- libffi-dev, zlib1g-dev, libssl-dev, libgdbm-dev: common dev headers
- libreadline-dev, libyaml-dev: additional Ruby dependencies
- ruby-dev: Ruby development headers
- unzip, ca-certificates: binary extraction and verification

Resolves sass-embedded 1.93.3 compilation failure in GitHub Actions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: calderbuild

.github/workflows/jekyll.yml

@@ -33,6 +33,24 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+
+      - name: Install build dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            build-essential \
+            gcc g++ make \
+            pkg-config \
+            libffi-dev \
+            zlib1g-dev \
+            libssl-dev \
+            libgdbm-dev \
+            libreadline-dev \
+            libyaml-dev \
+            ruby-dev \
+            unzip \
+            ca-certificates
+
       - name: Setup Ruby
         # https://github.com/ruby/setup-ruby/releases/tag/v1.207.0
         uses: ruby/setup-ruby@4a9ddd6f338a97768b8006bf671dfbad383215f4