Add rmagick dependency to workflow

Author: Pyrofab

.github/workflows/build_check.yml

@@ -12,7 +12,7 @@ jobs:
           fetch-depth: 0
           filter: tree:0
       - name: Install ImageMagick
-        run: sudo apt-get install -y imagemagick
+        run: sudo apt-get install -y imagemagick libmagickwand-dev
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1
         with: