PNG library

Author: ifilot

.github/workflows/linux.yml

@@ -22,6 +22,7 @@ jobs:
             libglfw3-dev \
             libglm-dev \
             libgl1-mesa-dev \
+            libpng-dev \
             libx11-dev \
             libxi-dev \
             libxrandr-dev \

.github/workflows/windows.yml

@@ -23,6 +23,7 @@ jobs:
             mingw-w64-x86_64-toolchain
             mingw-w64-x86_64-cmake
             mingw-w64-x86_64-glew
+            mingw-w64-x86_64-libpng
             mingw-w64-x86_64-glfw
             mingw-w64-x86_64-glm