Install cairo on mac

Author: TeofilC

.github/workflows/ci.yml

@@ -40,7 +40,7 @@ jobs:
         run: sudo apt-get update && sudo apt-get install libgtk2.0-dev
       - name: Install system dependencies (macOS)
         if: runner.os == 'macOS'
-        run: brew install gtk+ pkg-config
+        run: brew install cairo gtk+ pkg-config
       - name: Set extra cabal build options (macOS)
         if: runner.os == 'macOS'
         run: echo "CABAL_BUILD_OPTIONS=--constraint='gtk +have-quartz-gtk'" >> $GITHUB_ENV