[ci] Install required libfontconfig1-dev dependency

Author: dacap

.github/workflows/build.yml

@@ -37,7 +37,7 @@ jobs:
           sudo apt-get install -y \
             libc++-dev libc++abi-dev \
             libpixman-1-dev libfreetype6-dev libharfbuzz-dev zlib1g-dev \
-            libx11-dev libxcursor-dev libxi-dev libgl1-mesa-dev
+            libx11-dev libxcursor-dev libxi-dev libgl1-mesa-dev libfontconfig1-dev
           if [[ "${{ matrix.backend }}" == "skia" ]] ; then
             wget https://github.com/aseprite/skia/releases/download/m102-861e4743af/Skia-Linux-Release-x64-libc++.zip
             unzip Skia-Linux-Release-x64-libc++.zip -d skia